KIT and acute myeloid leukemia: The stem cell factor receptor, KIT, is a receptor tyrosine kinase that has been found to be mutated and constitutively active in a number of human malignancies, including mast cell leukemia, core binding factor acute myeloid leukemia, gastrointestinal stromal tumors (GISTs), malignant melanoma and testicular carcinoma (for review, see ref.1).