NPM1 and acute myeloid leukemia: Since it has been reported that prolonged (in contrast to intermittent) XPO1 inhibition down-regulates the HOX/MEIS axis, inducing the differentiation of the NPM1-mutated AML cells, the more frequent administration of the second-generation XPO1 inhibitor eltanexor (KPT-8602) has been proposed.