STAT3 and prostate cancer: Hence, STAT-3 inhibition by STT has been reported to increase apoptosis in several in vitro studies on nasopharyngeal, esophageal, ovarian, and prostate cancer cell lines [17,18,19,20], as well as in vivo xenograft models of colorectal cancer, diffuse large B-cell lymphoma, and prostate cancer [21,22,23].