As Flavopiridol, a pan-CDK inhibitor, has been shown to downregulate iNOS expression37, and c-Met signaling possibly acts as a regulator of the NF-κB-iNOS-NO pathway38, we believe that the negative correlations between iNOS expression and CDK4/6 and c-MET inhibitor EC50 values indicate that iNOS plays an important role in PDAC tumor cells. This evidence concerns the gene NFKB1 and neoplasm.