hENT1 and hCNT1 levels correlate with gemcitabine sensitivity and OS, making them good predictive markers for gemcitabine response in pancreatic cancer patients as high hENT1 expression is associated with longer OS and disease-free survival (DFS) of pancreatic cancer patients [63,69,71,73]. This evidence concerns the gene SLC28A1 and familial pancreatic carcinoma.