Mutational analysis should include KRAS and NRAS codons 12 and 13 of exon 2, 59, and 61 of exon 3, and 117 and 146 of exon 4 (“expanded” or “extended” RAS). BRAF p.V600 (BRAF c.1799 [p.V600]) mutational analysis should be performed in CRC tissue in patients with colorectal carcinoma for prognostic stratification. The gene discussed is KRAS; the disease is colorectal carcinoma.