NPM1 and acute myeloid leukemia: We first measured the expression levels of HOXB-AS3 in six AML cell lines with wild-type NPM1 (NPM1wt) (Kasumi-1, K-562, KG-1a, MOLM-13, MV-4-11, and THP-1) and in the NPM1mut OCI-AML3 cell line, which harbors Type A NPM1 mutations, by custom-designed real-time quantitative PCR (RT-qPCR) (Supplementary Table 1a).