DEC1 is wildly expressed in most normal human tissues, but only in a proportion of cells, while in tumors, expression of DEC1 is thought to be induced by hypoxia and was detected up-regulated in several kinds of malignancies, including breast, stomach, colon, lung, liver, and pancreatic ductal adenocarcinoma [28], [29], [30], [31], [32], [33], [34]. Here, BHLHE40 is linked to pancreatic ductal adenocarcinoma.