DCK and leukemia: 2-Chloro-2′-deoxy-2′-[18F]fluoro-9-β-d-arabinofuranosyladenine (76) ([18F]-CFA) has also been recently explored as a tracer for deoxycytidine kinase (dCK) activity.196 [18F]-CFA (76) showed accumulation in leukemia cells in correlation with dCK expression.