A meta-analysis study of NUDT15 variants investigating 1,752 patients from 7 independent cohorts (both ALL and IBD) showed a significant association between NUDT15 rs116855232 T allele and myelotoxicity: indeed, the presence of the T allele increases ~8 times the probability to have leukopenia in comparison to the C allele (P < 0.00001, OR = 7.86, 95% CI: 6.13, 10.08). Here, NUDT15 is linked to Decreased total leukocyte count.