Qualitative hematological toxicity variables, including thrombocytopenia, leukopenia, neutropenia, lymphocytopenia, and anemia, were assessed at five different time points for their correlation with various alleles of the CYP2C19, ALDH3A1, SLC22A16, and ABCB1 genes. This evidence concerns the gene SLC22A16 and Decreased total leukocyte count.