Cytoplasmic localization of phosphorylated Stat5 in myeloid leukemia. (A) Immunohistochemical detection of P-Y-Stat5 in neoplastic cells from patients with CML. P-Y-Stat5 immunostaining was realized on normal bone marrow (BM), on neoplastic cells from CML in chronic phase (CML-cp), in blast phase (CML-pb), and in megakaryoblast crisis. (B) Cytoplasmic and nuclear extracts were prepared from leukemic cells of a patient with CML and analyzed by Western blot with the indicated antibodies. (C) Immunohistochemical detection of P-Y-Stat5 in AML blasts. P-Y-Stat5 immunostaining was performed with bone marrow sections from patients AML-M2, -M3, -M6, and -M7.