More recently, FTY720 has been investigated for the treatment of malignancies and has documented in vitro and/or pre-clinical activity against a number of hematological disorders including T-cell acute lymphoblastic leukemia (T-ALL), multiple myeloma, chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), acute myeloid leukemia (AML) with c-kit mutations, mouse models of chronic myeloid leukemia (CML) and Ph+ (Philadelphia chromosome positive) ALL, Ph− ALL and NK cell leukemia [6], [7], [8], [9], [10], [11], [12], [13]. The gene discussed is KIT; the disease is acute lymphoblastic leukemia.