(30) found Equilibrative nucleoside Transporter-1 (hENT1) in humans, Deoxycytidine kinase (dCK), ribonucleotide reductase catalytic subunit M1 (RRM1), and RRM2 is associated with gemcitabine resistance acquired in pancreatic cancer cells. This evidence concerns the gene SLC29A1 and familial pancreatic carcinoma.