A prior study also revealed an unforeseen tumor suppressor role for Notch1 in a K-ras-induced PDAC murine model, where K-ras is activated and Notch1 is deleted.504 In this model, the absence of Notch1 results in increased tumor occurrence and advancement, suggesting that Notch1 may act as a tumor suppressor in K-ras-induced PDAC. This evidence concerns the gene NOTCH1 and neoplasm.