Conversely, evidence gleaned from a randomized phase II trial indicated that the concomitant use of checkpoint inhibitors (durvalumab and tremelimumab) with chemotherapy agents (gemcitabine and nab-paclitaxel) did not confer a survival advantage in patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) compared to chemotherapy alone.[54] These findings raise the intriguing possibility that the anatomical origin of KRAS mutations may influence the therapeutic efficacy of combined modalities. This evidence concerns the gene KRAS and pancreatic ductal adenocarcinoma.