ARID1A and gastric cancer: ARID1A, an AT-rich interactive domain-containing protein 1A, is a component of the switching defective/sucrose non-fermenting (SWI/SNF) complex that plays a role in chromatin remodeling (19), and increasing evidence suggests that ARID1A alterations are correlated with better outcomes after ICI therapy for bladder cancer, nonsmall-cell lung cancer (NSCLC), and gastric cancer (20, 21).