Exhibit 99.1

Illumina Reports Financial Results for Fourth Quarter and Fiscal Year 2011

San Diego, Calif., February 7, 2012 — Illumina, Inc. (NASDAQ:ILMN) today announced its financial results for the fourth quarter and fiscal year of 2011.

Fourth quarter 2011 results:

Gross margin in the fourth quarter of 2011 was 68.2% compared to 63.6% in the prior year period. Excluding the effect of non-cash charges associated with stock compensation and the amortization of acquired intangibles, non-GAAP gross margin was 70.2% for the fourth quarter of 2011 compared to 65.1% in the prior year period.

Research and development (R&D) expenses for the fourth quarter of 2011 were $45.5 million compared to $45.8 million in the fourth quarter of 2010. R&D expenses included $7.3 million and $7.0 million of non-cash stock compensation expense in the fourth quarters of 2011 and 2010, respectively. Excluding these charges and contingent compensation expense, R&D expenses as a percentage of revenue were 15.0% compared to 14.5% in the prior year period.

Selling, general and administrative (SG&A) expenses for the fourth quarter of 2011 were $60.9 million compared to $62.0 million for the fourth quarter of 2010. SG&A expenses included $12.7 million and $11.3 million of non-cash stock compensation expense in the fourth quarters of 2011

and 2010, respectively. SG&A expenses in the fourth quarter of 2011 also included $2.3 million in legal settlement gain and amortization of acquired intangibles. Excluding these items, SG&A expenses as a percentage of revenue were 20.1% compared to 19.4% in the prior year period.

The company generated $108.3 million in cash flow from operations during the fourth quarter of 2011 compared to $81.5 million in the prior year period. Depreciation and amortization expenses were $18.5 million and capital expenditures were $27.1 million during the fourth quarter of 2011. The company ended the fourth quarter of 2011 with $1.2 billion in cash, cash equivalents and short-term investments compared to $894.3 million as of January 2, 2011.

Fiscal 2011 results:

Gross margin for fiscal 2011 was 67.2% compared to 66.6% in fiscal 2010. Excluding the effect of non-cash charges associated with stock compensation and the amortization of acquired intangibles, non-GAAP gross margin was 69.0% in fiscal 2011 compared to 68.1% in fiscal 2010.

R&D expenses for fiscal 2011 were $196.9 million compared to $177.9 million in fiscal 2010. R&D expenses for fiscal 2011 included non-cash stock compensation expense of $32.1 million compared to $25.4 million in fiscal 2010. R&D expenses also included contingent compensation expense of $4.8 million in fiscal 2011 and $3.7 million in fiscal 2010. Excluding these charges, R&D expenses as a percentage of revenue were 15.2% compared to 16.5% in fiscal 2010.

SG&A expenses for fiscal 2011 were $261.8 million compared to $220.5 million in fiscal 2010. SG&A expenses included $52.3 million and $40.4 million of non-cash stock compensation expense in fiscal 2011 and 2010, respectively. SG&A expenses in fiscal 2011 also included $2.3 million in legal settlement gain, $1.3 million of contingent compensation expense and amortization of acquired intangibles. Excluding these items, SG&A expenses as a percentage of revenue were 19.9%, consistent with fiscal 2010.

The company generated $358.1 million in cash flow from operations in fiscal 2011 compared to $272.6 million in fiscal 2010. Depreciation and amortization expenses for fiscal 2011 were $68.3 million and capital expenditures were $77.8 million.

Highlights since our last earnings release

Financial outlook and guidance

The non-GAAP financial guidance discussed below excludes various one-time or specified non-cash charges. Please see our Reconciliation of Non-GAAP Financial Guidance included in this release for a reconciliation of the GAAP and non-GAAP financial measures.

We currently expect revenue for 2012 between $1.10 billion and $1.175 billion, representing year-over-year growth between 4% and 11%. We expect our non-GAAP gross margin percentage to approximate 70% for the year. We expect non-GAAP earnings per fully diluted share between $1.40 and $1.50. We expect the full-year pro forma tax rate to be approximately 33% and stock compensation expense to be approximately $105 million. The Company expects full-year weighted average diluted shares outstanding for the measurement of pro forma amounts to be approximately 135 million shares.

For the first quarter of 2012, we expect revenues between $250 and $260 million and a non-GAAP gross margin percentage of approximately 69%. We expect non-GAAP earnings per fully diluted share of $0.29 to $0.32, assuming approximately 133 million shares. We expect stock compensation expense during the first quarter of approximately $25 million.

Quarterly conference call information

The conference call will begin at 2:00 pm Pacific Time (5:00 pm Eastern Time) on Tuesday, February 7, 2012. Interested parties may listen to the call by dialing 888-455-2265 (passcode: 8701498), or if outside North America by dialing +1-719-457-2637 (passcode: 8701498). Individuals may access the live teleconference in the Investor Relations section of Illumina’s web site under the “Company” tab at www.illumina.com.

A replay of the conference call will be available from 5:00 pm Pacific Time (8:00 pm Eastern Time) on February 7, 2012 through February 14, 2012 by dialing 888-203-1112 (passcode: 8701498), or if outside North America by dialing +1-719-457-0820 (passcode: 8701498).

Statement regarding use of non-GAAP financial measures

The company reports non-GAAP results for diluted net income per share, net income, gross margins, operating expenses, operating margins, other income, and free cash flow in addition to, and not as a substitute for, or superior to, financial measures calculated in accordance with GAAP.

The company’s financial measures under GAAP include substantial charges related to stock compensation expense, headquarter relocation expense, non-cash interest expense associated with the company’s convertible debt instruments that may be settled in cash, restructuring charges, amortization expense related to acquired intangible assets, loss on the extinguishment of convertible debt, contingent compensation expense, legal settlement gain, and acquisition related gain or expense. Per share amounts also include the double dilution associated with the accounting treatment of the company’s 0.625% convertible senior notes outstanding and the corresponding call option overlay. Management believes that presentation of operating results that excludes these items and per share double dilution provides useful supplemental information to investors and facilitates the analysis of the company’s core operating results and comparison of operating results across reporting periods. Management also believes that this supplemental non-GAAP information is therefore useful to investors in analyzing and assessing the company’s past and future operating performance.

The company encourages investors to carefully consider its results under GAAP, as well as its supplemental non-GAAP information and the reconciliation between these presentations, to more fully understand its business. Reconciliations between GAAP and non-GAAP results are presented in the tables of this release.

Use of forward looking statements

This release contains projections, information about our financial outlook, earnings guidance, and other forward-looking statements that involve risks and uncertainties. These forward-looking statements are based on our expectations as of the date of this release and may differ materially from actual future events or results. Among the important factors that could cause actual results to differ materially from those in any forward-looking statements are (i) our ability to develop and commercialize further our sequencing, array, PCR, and consumables technologies and to deploy new products and applications, and expand the markets, for our technology platforms; (ii) our ability to manufacture robust instrumentation and consumables;

(iii) our expectations and beliefs regarding future conduct and growth of the business and the markets in which we operate; (iv) challenges inherent in developing, manufacturing, and launching new products and services; (v) business disruptions associated with the tender offer commenced by CKH Acquisition Corporation, a wholly owned subsidiary of Roche Holding Ltd; (vi) our ability to maintain our revenue and profitability during periods of research funding reduction or uncertainty and adverse economic and business conditions, including as a result of slowing economic growth in the United States or worldwide, together with other factors detailed in our filings with the Securities and Exchange Commission, including our most recent filings on Forms 10-K and 10-Q, or in information disclosed in public conference calls, the date and time of which are released beforehand. We undertake no obligation, and do not intend, to update these forward-looking statements, to review or confirm analysts’ expectations, or to provide interim reports or updates on the progress of the current financial quarter.

About Illumina

Illumina (www.illumina.com) is a leading developer, manufacturer, and marketer of life science tools and integrated systems for the analysis of genetic variation and function. We provide innovative sequencing and array-based solutions for genotyping, copy number variation analysis, methylation studies, gene expression profiling, and low-multiplex analysis of DNA, RNA, and protein. We also provide tools and services that are fueling advances in consumer genomics and diagnostics. Our technology and products accelerate genetic analysis research and its application, paving the way for molecular medicine and ultimately transforming healthcare.

Additional Information and Where to Find It

This communication does not constitute an offer to buy or a solicitation of an offer to sell any securities. In response to the tender offer commenced by CKH Acquisition Corporation, a wholly owned subsidiary of Roche Holding Ltd, Illumina has filed a solicitation/recommendation statement on Schedule 14D-9 with the SEC. INVESTORS AND SECURITY HOLDERS OF ILLUMINA ARE URGED TO READ THE SOLICITATION/RECOMMENDATION STATEMENT AND OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY IN THEIR ENTIRETY (WHEN THEY BECOME AVAILABLE) BECAUSE THEY CONTAIN IMPORTANT INFORMATION. Investors and security holders will be able to obtain free copies of these documents (when they become available) and other documents filed with the SEC by Illumina through the web site maintained by the SEC at http://www.sec.gov. Investors and security

holders also will be able to obtain free copies of these documents, and other documents filed with the SEC by Illumina, from Illumina by directing a request to Illumina, Inc., Attn: Investor Relations, Kevin Williams, MD, kwilliams@illumina.com.

In addition, Illumina will file a proxy statement and a WHITE proxy card with the SEC. The definitive proxy statement will be mailed to security holders of Illumina. INVESTORS AND SECURITY HOLDERS OF ILLUMINA ARE URGED TO READ THE PROXY STATEMENT AND OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY IN THEIR ENTIRETY (WHEN THEY BECOME AVAILABLE) BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION. Investors and security holders will be able to obtain free copies of these documents (when they become available) and other documents filed with the SEC by Illumina through the web site maintained by the SEC at http://www.sec.gov. Investors and security holders also will be able to obtain free copies of the proxy statement, and other documents filed with the SEC by Illumina, from Illumina by directing a request to Illumina, Inc., Attn: Investor Relations, Kevin Williams, MD, kwilliams@illumina.com.

Certain Information Regarding Participants in the Solicitation

Illumina and certain of its directors and executive officers may be deemed to be participants in the solicitation of proxies in connection with Illumina’s 2012 Annual Meeting of Stockholders under the rules of the SEC. Security holders may obtain information regarding the names, affiliations and direct and indirect interests (by security holdings or otherwise) of Illumina’s directors and executive officers in (i) Illumina’s Annual Report on Form 10-K for the year ended January 2, 2011, which was filed with the SEC on February 28, 2011, and (ii) Illumina’s proxy statement for its 2011 Annual Meeting of Stockholders, which was filed with the SEC on March 24, 2011. To the extent that Illumina’s directors’ and executive officers’ holdings of Illumina’s securities have changed from the amounts printed in the proxy statement for the 2011 Annual Meeting of Stockholders, such changes have been or will be reflected on Statements of Changes in Beneficial Ownership on Form 4 filed with the SEC. These documents can be obtained free of charge from the sources indicated above. Additional information regarding the interests of these participants in any proxy solicitation and a description of their direct and indirect interests, by security holdings or otherwise, will also be included in any proxy statement and other relevant materials to be filed with the SEC when they become available.

# # #

Investors:

Kevin Williams, MD

Investor Relations

858-332-4989

kwilliams@illumina.com

or

Media:

Laura Trotter

Public Relations

858-882-6822

PR@illumina.com

Illumina, Inc.

Condensed Consolidated Balance Sheets

(In thousands)

Illumina, Inc.

Condensed Consolidated Statements of Income

(In thousands, except per share amounts)

(unaudited)

Illumina, Inc.

Condensed Consolidated Statements of Cash Flows

(In thousands)

(unaudited)

Illumina, Inc.

Results of Operations — Non-GAAP

(In thousands, except per share amounts)

(unaudited)

ITEMIZED RECONCILIATION BETWEEN GAAP AND NON-GAAP NET INCOME PER SHARE:

2011 adjustments:

2010 adjustments:

Illumina, Inc.

Results of Operations — Non-GAAP (continued)

(Dollars in thousands)

(unaudited)

ITEMIZED RECONCILIATION BETWEEN GAAP AND NON-GAAP RESULTS OF OPERATIONS AS A PERCENT OF REVENUE:

2011 adjustments:

2010 adjustments:

Illumina, Inc.

Reconciliation of Non-GAAP Financial Guidance

The financial guidance provided below is an estimate based on information available as of February 7, 2012. The company’s future performance and financial results are subject to risks and uncertainties, and actual results could differ materially from the guidance set forth below. Some of the factors that could affect the company’s financial results are stated above in this press release. More information on potential factors that could affect the company’s financial results is included from time to time in the company’s public reports filed with the SEC, including the company’s Form 10-K for the fiscal year ended January 1, 2012 to be filed with the SEC, and the company’s Form 10-Q for the fiscal quarters ended April 3, 2011, July 3, 2011, and October 2, 2011. The company assumes no obligation to update any forward-looking statements or information, which speak as of their respective dates.