A specific R366C/H SAMHD1 mutation has been found in leukaemia and colon cancers, which ablates the dNTP hydrolase activity of SAMHD1 while retaining catalytic-independent functions, and could thus mechanistically contribute to elevated dNTP pools in cancer cells (Bowen et al., 2021). The gene discussed is SAMHD1; the disease is malignant colon neoplasm.