Consistent with these findings, the expression level of HOTAIRM1 was measured by qRT-PCR in 34 primary AML blasts, and HOTAIRM1 was found to be highly expressed in NPM1-mutated AML cases (n = 14) compared with NPM1- unmutated AML cases (n = 20) (Fig. 1e). This evidence concerns the gene NPM1 and acute myeloid leukemia.