The pathogenicity of somatic MYH mutations is thought to primarily arise from the accumulation of G:C → T:A transversions in APC, which results in carriers of monoallelic disease-causing MUTYH strain variants having a higher risk of developing tumors.138 A diverse array of somatic MYH mutations, including both nonsense and missense variants, have been identified in CRC patients.139 It is noteworthy that some patients exhibit only a single detectable somatic MYH mutation, suggesting the presence of other elusive mutations.140 When both alleles of MYH are mutated, the penetrance is very high. The gene discussed is MUTYH; the disease is colorectal carcinoma.