Unlike other cancers that are associated with KRAS mutations, CRC is unique for its diversity of KRAS alleles, with the most common being G12D (28%), G12V (20%), and G13D (16%).4,5 Like other small GTPases, KRAS acts as a binary molecular switch between an active GTP-bound state and an inactive GDP-bound state. The gene discussed is KRAS; the disease is cancer.