In a recent U.S. pan-cancer study, TP53 (34.5%), PIK3CA (13.5%), LRP1B (13.1%), KRAS (10.5%), APC (10.1%), FAT4 (9.5%), KMT2D (9.2%), KMT2C (9.1%), BRAF (7.7%), and ARID1A (7.0%) were identified as the top mutated cancer genes for the U.S. The gene discussed is ARID1A; the disease is cancer.