Objective methods for diagnosing a predisposition to developing pancreatic cancer and prostate cancer, particularly pancreatic ductal adenocarcinoma (PDAC) and castration-resistant prostate cancer, are described herein. In one embodiment, the diagnostic method involves the step of determining an expression level of C12ORF48 using siRNAs targeting the C12ORF48 gene. The invention also features products such as siRNAs as well as to compositions containing them. The present invention further provides methods of screening for therapeutic agents useful in the treatment of C12ORF48 associated disease, such as a cancer, e.g. pancreatic cancer and prostate cancer, as well as methods of inhibiting the cell growth and treating or alleviating one or more disease symptoms. The invention also features products such as double stranded molecules, as well as vectors and compositions containing them.