p53 and p21—different p53 isoforms associated with FLT3-ITD and NPM1 mutations: p53 inhibits G1 progression through p2 induction. p53 is mutated only in a minority of AML patients; but the balance between various isoforms differ between patients, e.g., between patients with adverse prognosis FLT3-ITD and NPM1 mutations [107]. Here, FLT3 is linked to acute myeloid leukemia.