PIK3CA and colorectal carcinoma: KRAS mutations usually co-occur with mutations in tumor protein p53 (TP53) and cyclin-dependent kinase inhibitor 2A (CDKN2A) in PDAC, Kelch-like ECH-associated protein 1 (KEAP1) and/or serine/threonine kinase 11 (STK11) in NSCLC, or APC regulator of WNT signaling pathway (APC) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) in CRC.