TNFSF10 and ovarian cancer: Biomarkers to predict the functionality of the TRAIL apoptotic pathway in cancer cells are becoming increasingly important with emerging promising phase I trials and new pre-clinical studies showing the potency of TRAIL on the tumor vasculature and synergistic DR5-activation by the combination of TRAIL and agonistic DR5 antibody (AMG655, Amgen) in ovarian cancer [3, 13].