Gervasini G, et al. - The impact of polymorphisms were comprehensively analyzed in the regulatory regions of the dihydrofolate reductase (DHFR) gene correlated with methotrexate (MTX) dose adjustments and drug-induced toxicity, among children on maintenance therapy for acute lymphoblastic leukemia (ALL). The yielded data illustrated that the detection of DHFR polymorphisms in the promoter region of the gene could be beneficial in customizing the MTX doses for ALL pediatric patients on maintenance therapy.