In order to optimize HD-MTX therapy and reduce related hematopoietic toxicity, it is necessary to detect the SNPs of MTHFR and ABCB1 before initiating HD-MTX and decide the optimal dose of MTX and duration of leucovorin rescue, according to the results of genetic tests and disease type in adults with hematological malignancies. Here, MTHFR is linked to hematologic disorder.