Rapid metabolic inactivation of gemcitabine is predominantly catalysed by Cda or deoxycytidylate deaminase (Dctd).30 To investigate the mechanism of increased levels of dFdCTP in fibroblasts, we determined mRNA expression of a comprehensive panel of 15 genes involved in gemcitabine transport and metabolism (Ent1, Ent2, Cnt1, Cnt2, Nt5c1A, Nt5c3, Dctd, Rrm1, Rrm2, Rrm2b, Rpe, Rpia, TK2, dCK and Cda) in primary cell lines from pancreatic tumours, liver metastases and fibroblasts (PSCs and CAFs). The gene discussed is RRM2; the disease is pancreatic neoplasm.