Activating mutations of KIT (encoding a transmembrane glycoprotein) leading to constitutional activation of receptor tyrosine kinase pathway, similar to systemic mastocytosis, GIST and germ cell tumors, are most commonly observed in “core binding factor” (CBF) leukemias which encompass AML with t(8;21) and AML with inv(16). This evidence concerns the gene NTRK1 and acute myeloid leukemia.