NRAS and colorectal carcinoma: Similarly, a provisional guideline from the Association of Clinical Pathologists Molecular Pathology and Diagnostics Group in the United Kingdom also recommends that at least KRAS codons 12, 13, 59, 61, 117, and 146 and NRAS codons 12, 13, 59, and 61 should be included for molecular analysis in CRC patients [17].