NUMB and chronic myelogenous leukemia, BCR-ABL1 positive: Specifically, Ito et al. reported in Nature that the Musashi-Numb pathway can control the differentiation of Chronic myelogenous leukemia (CML); expression of Numb as a result of MSI2 loss impairs the development and propagation of blast crisis CML in vitro and in vivo [6].