Combined with our previous findings that oxidative stress induces ADAM9 expression in prostate cancer cells [13], and knockdown of ADAM9 sensitizes prostate cancer cells to ionizing irradiation and chemotherapeutic agents including doxorubicin, cisplatin, taxotere, gemcitabine, and etoposide [16], these results reveal a novel regulatory pathway of this oncoprotein in protecting cancer cells against oxidative damage and other stressors in the prostate tumor microenvironment. The gene discussed is ADAM9; the disease is prostate carcinoma.