FLT3 and acute myeloid leukemia: Additionally, pimozide has been found to inhibit the in vitro phosphorylation of STAT5 in BCR-ABL positive and pSTAT5 overexpressing K562 chronic lymphocytic leukemia (CLL) cell lines [64,65], as well as in mice models with acute myeloid leukemia that contain the FLT3 internal tandem duplication (ITD) mutation [66].