In a study on the influence of RFC1 SNPs and haplotypes on HD-MTX-induced toxicities in 88 adolescents and children with ALL, authors revealed that the rs2838958 TT genotype were more likely to develop mucositis in patients, compared to carriers with at least one rs2838958 C allele, and haplotype TGTTCCG (H4) notably decreased the risk of adverse events in response to HD-MTX therapy (Kotnik et al., 2017). Here, RFC1 is linked to acute lymphoblastic leukemia.