AT-rich interaction domain 1A (ARIDA), which encodes the BAF250a subunit of the Switch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex (Mandal et al., 2022), is recurrently mutated across cancers, including ovarian clear cell (Jones et al., 2010), endometrial (Wiegand et al., 2010), and gastric carcinomas (Wang et al., 2011). The gene discussed is ARID1A; the disease is gastric carcinoma.