Importantly, the decrease in CTP levels was not dependent in the presence of a wild-type dCK activity, as the human NSCLC cell line SWg, which has a disrupted dCK gene (van Bree et al, 2002; Jordheim et al, 2004), showed similar CTP depletion as compared to its parental cell line SWp. Here, DCK is linked to non-small cell lung carcinoma.