PIK3CA and urinary bladder cancer: In addition to the PIK3CA mutations, we found signatures 2 and 13 to be associated with ERBB2 p.S310F (c.929C>T) mutation in bladder cancer, and signature 13 to be associated with PPP2R1A p.P179R (c.536C>G) mutation in uterine corpus endometrial carcinoma (Table 2).