ARID1A and cancer: Recently, a novel tumor suppressor AT-rich interactive domain-containing protein 1A (ARID1A) has been found to be frequently mutated in human cancers, including 8–27% of GCs [1–5], 57% of ovarian clear-cell carcinomas (OCCC) [6], 23–42% of endometrioid carcinomas [7, 8], 17% of Burkitt lymphomas [9], 6.0–8.3% of lymphoma [10, 11], 10–16.8% of liver cancers [12–14] and 3–8% of lung cancers [15–17].