Personalis Prices Initial Public Offering of Common Stock

Personalis, Inc., a leader in advanced genomics for cancer, today announced the pricing of its initial public offering of 7,921,500 shares of common stock at a price to the public of $17.00 per share. All of the shares of common stock are being offered by Personalis. In addition, Personalis has granted the underwriters a 30-day option to purchase up to an additional 1,188,225 shares of common stock from Personalis at the public offering price less underwriting discounts and commissions. The company's shares are expected to begin trading on The Nasdaq Global Market on Thursday, June 20, 2019 under the trading symbol "PSNL." The offering is expected to close on June 24, 2019, subject to the satisfaction of customary closing conditions.

Morgan Stanley, BofA Merrill Lynch and Cowen are acting as joint book-running managers for the offering. Oppenheimer & Co. Inc. is acting as co-manager for the offering.

A registration statement relating to these securities has been filed with the U.S. Securities and Exchange Commission and was declared effective on June 19, 2019. A copy of the final prospectus relating to this offering may be obtained, when available, from: Morgan Stanley & Co. LLC, Attention: Prospectus Department, 180 Varick Street, 2nd Floor, New York, New York 10014, or by email at [email protected]; BofA Securities, Inc., Attention: Prospectus Department, NC1?004?03?43, 200 North College Street, 3rd floor, Charlotte, NC 28255?0001, or by emailing [email protected]; or Cowen and Company, LLC, c/o Broadridge Financial Solutions, Attention: Prospectus Department, 1155 Long Island Avenue, Edgewood, New York 11717, telephone: 631?274?2806.

This press release shall not constitute an offer to sell or a solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About Personalis, Inc.

Personalis, Inc. is a growing cancer genomics company transforming the development of next-generation therapies by providing more comprehensive molecular data about each patient's cancer and immune response. The company's NeXTtm Platform is designed to adapt to the complex and evolving understanding of cancer, providing its biopharmaceutical customers with information on all of the approximately 20,000 human genes, together with the immune system, from a single tissue sample. The Personalis Clinical Laboratory is GxP aligned as well as CLIA'88-certified and CAP-accredited. For more information, please visit www.personalis.com and follow Personalis on Twitter (@PersonalisInc).