NRAS and colorectal carcinoma: Matching with what we have mentioned before, we have detected somatic mutations in eleven CRC patients (18%) that are linked to the resistance to anti-EGFR target therapy, three variants in KRAS located on exon 2, one mutation in NRAS located on exon 2, one BRAFV600, two non-BRAFV600 mutations located on exon 15, and one PIK3CA mutation located on exon 20.