TPMT and Decreased total leukocyte count: To determine the best method to predict severe leukopenia and alopecia, they performed GWAS and showed that NUDT15 c.415C>T had the strongest association with severe leukopenia and alopecia (p = 1.3 × 10−33 and 4.3 × 10−29, respectively), while previouslyreported variants of TPMT, ABCC4, and RUNX1 were not associated with.