Experimental alterations of Meis1 expression are associated with severe, often fatal, prenatal developmental defects in neurologic patterning, the differentiation of hematopoietic stem cells and establishment of definitive hematopoiesis, peripheral angiogenesis, cardiomyocyte cell-cycle regulation, and hematopoietic cancers; but in no case has Meis1 expression been associated with fetal or postnatal growth rates or nutrient acquisition per se. This evidence concerns the gene MEIS1 and hematopoietic and lymphoid cell neoplasm.