Results indicated that the SAMHD1 promoter was methylated in all T-ALL cell lines but one (MOLT-16) (Fig. 6a), which was the only T-ALL cell line characterised by high SAMHD1 mRNA and protein levels (Fig. 3) and low AraG sensitivity (Supplementary Table 3). The gene discussed is SAMHD1; the disease is acute lymphoblastic leukemia.