In this study, we aimed at determining the role of CAV1 alterations potentially induced by stromal CAV1-deficiency for the radio sensitivity of prostate cancer on molecular level and identified the apoptosis inhibitor TRIAP1 as a CAV1-dependent fibroblastic secreted factor, fostering radio resistance of malignant prostate epithelial cells. The gene discussed is TRIAP1; the disease is prostate carcinoma.