PIK3CA and colorectal carcinoma: Among 552 CRC cases analyzed, mutations were most frequently detected in the following genes: TP53, KRAS, APC, KDR, PIK3CA, SMAD4, BRAF, FBXW7, NRAS, MET, and PTEN. Similar mutation frequencies were reported in a study that analyzed more than 400 genes in 1134 CRC cases, as well as in a study by El-Deiry et al. that included 6892 cases and a 45-gene panel16,17.