BMAL1 and pancreatic ductal adenocarcinoma: Prospective analysis of circadian genes expression in patients with pancreatic ductal adenocarcinoma revealed lower expression of PER1, PER2, PER3, CRY1, CRY2, TIPIN, TIM, CK1E, BMAL-ARNTL, and CLOCK in cancer tissues compared to their matched adjacent tissue.