STAT3 and cancer: A downstream target of STAT3 is survivin; its increased expression is also associated with prostate cancer aggressiveness.171 mRNA expression levels of survivin in prostate biopsy tissues show significantly higher survivin expression in cancerous tissue, which correlates with higher-grade cancer and aggressive phenotypes.172 siRNA knockdown of survivin in prostate cancer cell lines reduces cell proliferation172 and increases chemosensitivity to the apoptosis-inducing agent cisplatin.173 The effects of decreased survivin expression extend in vivo.