This Annual Report contains forward-looking statements, including statements regarding our:

• projected timetables for the preclinical and clinical development of, regulatory submissions and approvals for, and market introduction of, our products and services in various jurisdictions, including Myozyme, sevelamer carbonate, Thyrogen, Aldurazyme, and Synvisc;
• timing of, and availability of data from, clinical trials;
• estimates of the potential markets for our products and services;
• the anticipated drivers for future growth of our products, including Renagel, Thymoglobulin and Synvisc;
• assessment of competitors and potential competitors and the anticipated impact of potentially competitive products on our revenues;
• estimates of the capacity of, and the projected timetable of approvals for, manufacturing and other facilities to support our products and services;
• expected future revenues, operations and expenditures;
• projected future earnings and earnings per share;
• assessment of the outcome and financial impact of litigation and other governmental proceedings and the potential impact of unasserted claims;
• sufficiency of cash, short-term investments and cash flows from operations;
• IRS audits, including our provision for liabilities and assessment of the impact on settlement of tax disputes;
• estimates of cost to complete and estimated commercialization dates for in-process research and development, or IPR&D, programs;
• assessment of deductibility of goodwill;
• assessment of the impact of recent tax legislation, including the American Jobs Creation Act, and recent accounting pronouncements, including Financial Accounting Standards Board, or FASB, Statement of Financial Accounting Standards, or SFAS, No. 123R regarding expensing of stock options, SFAS No. 151 regarding inventory costs, and SFAS No. 154 regarding accounting for changes and error corrections and FASB Staff Position, or FSP, Nos. 115-1 and 124-1;
• sales and marketing plans;
• expected future payments related to employee benefits and leased facilities acquired from Bone Care International, Inc., or Bone Care, Verigen AG, or Verigen, ILEX Oncology, Inc., or ILEX Oncology, Physician Services and Analytical Services business units of IMPATH Inc., or IMPATH, and SangStat Medical Corporation, or SangStat, and the expected timing of these payments;
• replacement of our revolving credit facility; and
• completion of a post-closing working capital assessment for our acquisition of substantially all of the pathology/oncology testing assets related to IMPATH.

These statements are subject to risks and uncertainties, and our actual results may differ materially from those that are described in this report. These risks and uncertainties include:

• our ability to successfully complete preclinical and clinical development of our products and services;
• our ability to secure regulatory approvals for our products and services, including Myozyme, and to do so on the anticipated timeframes;
• our ability to manufacture sufficient amounts of our products for development and commercialization activities and to do so in a timely and cost-effective manner;
• our ability to obtain and maintain adequate patent and other proprietary rights protection for our products and services and successfully enforce our proprietary rights;
• the scope, validity and enforceability of patents and other proprietary rights held by third parties and their impact on our ability to commercialize our products and services;
• the accuracy of our estimates of the size and characteristics of the markets to be addressed by our products and services, including growth projections;
• market acceptance of our products and services;
• the use of cash in business combinations or other strategic initiatives;
• our ability to identify new patients for our products and services;
• our ability to satisfy the post-marketing commitments made as a condition of the marketing approvals of Fabrazyme and Aldurazyme;
• the accuracy of our information regarding the products and resources of our competitors and potential competitors;
• the content and timing of submissions to and decisions made by the United States Food and Drug Administration, commonly referred to as the FDA, the European Agency for the Evaluation of Medicinal Products, or EMEA, and other regulatory agencies;
• the availability of reimbursement for our products and services from third-party payors, the extent of such coverage and the accuracy of our estimates of the payor mix for our products;
• our ability to increase market penetration outside the United States for our products;
• market acceptance of Synvisc, Thymoglobulin, Campath and Clolar in expanded areas of use and new markets;
• our ability to effectively manage wholesaler inventories of our products and the levels of compliance with our inventory management programs;
• our ability to establish and maintain strategic license, collaboration and distribution arrangements and to manage our relationships with collaborators, distributors and partners;
• our reliance on third parties to provide us with materials and services in connection with the manufacture of our products;
• the continued funding and operation of our joint ventures by our partners;
• our ability to successfully increase market penetration for Synvisc as a treatment for osteoarthritis of the knee and to expand its use in other joints;
• the resolution of litigation related to the consolidation of our tracking stocks;
• the initiation of legal proceedings by or against us;
• the impact of changes in the exchange rate for the Euro and other currencies on our product and service revenues in future periods;
• our ability to successfully integrate the manufacturing operation acquired from Cell Genesys Inc., or Cell Genesys, as well as the acquisitions of Bone Care, Equal Diagnostics, Inc., or Equal Diagnostics, ILEX Oncology and the businesses acquired from IMPATH;
• the number of diluted shares considered outstanding, which will depend on business combination activity, our stock price and potential changes in accounting rules;
• the outcome of our IRS audits; and
• the possible disruption of our operations due to terrorist activities and armed conflict, including as a result of the disruption of operations of regulatory authorities, our subsidiaries, our manufacturing facilities and our customers, suppliers, distributors, couriers, collaborative partners, licensees and clinical trial sites.

We have included more detailed descriptions of these and other risks and uncertainties under the heading "Factors Affecting Future Operating Results," in our Annual Report on Form 10-K filed with the SEC on March 10, 2006. We encourage you to read those descriptions carefully. We caution investors not to place substantial reliance on forward-looking statements. These statements, like all statements in the Annual Report, speak only as of the date of the report (unless another date is indicated) and we undertake no obligation to update or revise the statements. In addition, you should read individual statements appearing in our SEC filings with and in the context of the complete documents in which they appear, and any materials incorporated into those documents by reference, rather than as stand-alone documents.

Historical Information This is a summary of Genzyme Corporation's Annual Report. Certain information that is included in the Annual Report, including the financial statements and notes thereto, has been omitted. We encourage you to read the full Annual Report and qualify the information in this summary by reference to that filing. This summary is current as of March 10, 2006 and has not been updated to reflect changes in the business of Genzyme after that date. For current press releases, please visit the investors section of www.genzyme.com. For a full printed copy of the annual report, please download and print the on-line pdf file or email Genzyme.

Links to Genzyme's Website

Link to Form 10-K

Link to Investors Section

Link to PDF File

corpcom@genzyme.com