ABCC1 and familial pancreatic carcinoma: The deoxycytidine kinase (DCK), represents another key enzyme involved in gemcitabine phosphorylation/activation, and it has also been implicated in gemcitabine resistance [15], as well as the multidrug resistance-associated protein 1 (MRP1) which is involved in chemotherapy resistance in human pancreatic cancer [16,17].