X0206 3 2021-06-17 0 0001662244 Cyteir Therapeutics, Inc. CYT 0001864377 Naesens Janwillem 128 SPRING ST, BUILDING A, SUITE 510 LEXINGTON MA 02421 1 0 0 0 Series B Convertible Preferred Stock Common Stock 2933581 I See Footnote Series C Convertible Preferred Stock Common Stock 325442 I See Footnote Stock Option (Right to Buy) 18.00 2031-06-17 Common Stock 17250 D The shares of Series B Convertible Preferred Stock are convertible into the number of shares of the Issuer's common stock shown in column 3 and have no expiration date. The Series B Convertible Preferred Stock will automatically convert into common stock upon the closing of the Issuer's initial public offering. The shares of Series C Convertible Preferred Stock are convertible into the number of shares of the Issuer's common stock shown in column 3 and have no expiration date. The Series C Convertible Preferred Stock will automatically convert into common stock upon the closing of the Issuer's initial public offering. Shares held by Droia Invest II SCSp. DF II GP Sarl is the general partner of Droia Invest II SCSp. Wepaven BV (represented by Janwillem Naesens) and IHL SA (represented by the Reporting Person), the managers of DF II GP Sarl, share voting and investment power with respect to the shares held of record by Droia Invest II SCSp. The Reporting Person, along with Mr. Verelst, disclaim beneficial ownership of the securities reported herein, except to the extent of their pecuniary interest therein. The option will vest in full on the earlier of (a) June 17, 2022 and (b) the next annual meeting of stockholders that follows June 17, 2021, in each case subject to the Reporting Person's continued service on the Issuer's board of directors through the applicable vesting date. Exhibit List: Exhibit 24 - Power of Attorney By: /s/ Andrew Gengos, Attorney-in-Fact 2021-06-17