Quantificaiton of dCK phosphorylation at serine-74 (S74) with respect to total dCK in SAMHD1+/+ THP-1 cells treated with either solvent, 500 nM ara-C or a combination of 500 nM ara-C and an RNRi (HU, 50 µM; dF-dC, 10 nM; 3-AP, 150 nM) for 24 h. Circles and squares, columns and error bars correspond to individual measurements, means and s.e.m. of one representative out of two independent experiments performed in triplicates. 