Certain Class B Common Stock of Seer, Inc. are subject to a Lock-Up Agreement Ending on 27-JUL-2021. These Class B Common Stock will be under lockup for 181 days starting from 27-JAN-2021 to 27-JUL-2021. Details: Selling stockholders, in connection with this offering, other stockholders subject to lock-up agreements entered into in connection with initial public offering were given the opportunity to have a portion of the shares subject to such lock-ups released from the transfer restrictions contained in such agreements. Any such stockholder who requested up to 5% of their existing holdings to be released from the lock-ups was required to enter a new lock-up agreement with respect to such stockholder’s remaining shares, which expire 180 days after the date of this prospectus and and 365 days after the date of this prospectus for those selling stockholders selling greater than 5% and up to 15% of their existing holdings, may not (and may not cause any of their direct or indirect affiliates to), without the prior written consent of J.P. Morgan Securities LLC, Morgan Stanley & Co. LLC and BofA Securities, Inc.