STAT3 and breast cancer: Therefore, disruption of STAT3 signaling is associated with growth inhibition and apoptosis in cancer cell lines as well as in murine xenograft models of myeloproliferative neoplasms, acute lymphoblastic leukemia, glioblastoma, head and neck squamous cell carcinoma, breast cancer, lung adenocarcinoma and renal cell carcinoma [10, 13-15, 19, 22-28].