The incidences of leukopenia in intermediate/poor NUDT15 metabolizers (14.9% and 37.7%, respectively) patients were significantly higher than that in extensive NUDT15 metabolizers (NM; 9.4%) (P  =  4.47×10-14, OR = 1.85, 95% CI = 1.58–2.17). This evidence concerns the gene NUDT15 and Decreased total leukocyte count.