ATM and gastric cancer: When assessed in non–gastric cancer–focused early phase clinical trials, ATRi such as ceralasertib (AZD6738), berzosertib (M6620, VX-970) or elimusertib (BAY1895344) can elicit significant antitumor effects (22–29), including profound responses in prostate, breast, endometrial, renal, or appendiceal tumors, some of which have ATM or ARID1A defects (30, 31).