Inhibition of the SCF/c-Kit axis inhibits the migration of mouse bone marrow-derived cultured mast cells to tumors in a transplanted tumor model in mice (2), and mutations in c-Kit have been associated with the development of gastrointestinal stromal tumors, various forms of mastocytosis, and mast cell leukaemia (10). The gene discussed is KIT; the disease is mast cell leukemia.