KRAS and colorectal carcinoma: Indeed, our group and others have demonstrated that mutations in genes downstream of EGFR, namely in KRAS, BRAF and PIK3CA (the gene coding for p110α, the catalytic subunit of PI3K) are of particular relevance in microsatellite instable (MSI) and microsatellite stable (MSS) molecular subsets of CRC [4, 5].