Best model fits to neutrophil DNA enrichment data in subjects labeled with heavy water. Subjects were labeled with heavy water (2H2O) for 9 weeks (subjects A, B, C, D, E from Vrisekoop et al15 ) or 7 weeks (subjects DW04, DW09, DW10, and DW11 from the current study’s data). Circles represent measured fractional enrichment of deoxyadenosine in blood neutrophil DNA; lines represent best fits of the model (Equations 5 and 6) to the data.