ARID1A and gastric cancer: In another study on human primary gastric TP53−/− PDOs, knocking down the frequently mutated AT-rich interaction domain 1A (ARID1A) gene, led to a phenotype resembling ARID1A-mutant gastric cancers, particularly the MSI- (microsatellite instability) and (Epstein-Barr virus) EBV-associated subtypes, where ARID1A mutations are more common (Lo et al., 2021).