MSI2 and myeloid leukemia: Although both Msi1 and Msi2 are expressed in brain and testis, Msi2 is dominant in the hematopoietic tissues and functionally essential for normal hematopoietic stem cells and leukemia stem cells in myeloid leukemia (Ito et al, 2010; Park et al, 2014; Hattori et al, 2017).