Given the essential role that CNT1 plays in retaining dFdC in systemic circulation and biological tissues and the need to further evaluate the contribution of CNT1 to dFdC therapeutic efficacy, we next examined whether the loss of CNT1 alters dFdC drug efficacy in a syngeneic mouse model of pancreatic cancer. The gene discussed is SLC28A1; the disease is familial pancreatic carcinoma.