PIK3CA and colorectal carcinoma: We identified a large number of mutations in known CRC driver genes, including non-synonymous changes and stop codon gains in APC, KRAS, and PIK3CA. Notably, the number of mutations in CRC driver genes varied significantly within the cohort, ranging from two mutations in patients P1, P3, P10, and P18 (MSS) to 33 mutations in patient PP5 (MSI) (Fig. 1D).