Given the importance of DNA repair in DDP cytotoxicity and having available an ovarian carcinoma PDX platform which, as a whole, represents the complexity of human ovarian carcinoma and has been pharmacologically characterized in vivo for the response to platinum-based therapy [31], we investigated the roles of the ERCC1/XPF complex and DNA pol β as possible biomarkers of DDP response. The gene discussed is ERCC4; the disease is ovarian carcinoma.