Of the cancer types with 10 or more representative samples, PIK3CA and/or PTEN mutations were most prevalent in hepatocellular carcinoma samples (11/16; 69%), triple-negative breast-cancer samples (18/27, 67%), endometrial-carcinoma samples (10/17, 59%), and HR+ breast-cancer samples (31/61; 51%). The gene discussed is PIK3CA; the disease is cancer.