Furthermore, the MYC, DDX21, USP7, RFC4, APEX1, CDK9, and NOP2 of the “cancer cells_vs_all-PDAC” group play a critical role in the metabolic reprogramming of the PDAC, contributing to the poor prognosis of PDAC [61,62,63,64,65,66,67]. This evidence concerns the gene CDK9 and cancer.