Interestingly, activating mutations of the NT5C2 gene, known to elicit resistance to mercaptopurine anti-ALL treatment in pediatric cases [26, 27], are also observed across 3 adult cases exposed to this drug (Fig. 2a), with PAT16 bearing two mutations of NT5C2 (R238G, R367Q, see Additional file 1: Table S5). The gene discussed is NT5C2; the disease is acute lymphoblastic leukemia.