MTHFD1 and acute lymphoblastic leukemia: In contrast to these results, our previous study showed an influence of TYMS 2R>3R polymorphism on different haematotoxicitiesa, as well as an influence of MTHFD1 1958G>A polymorphism on hepatotoxicity grade ≥ 2 in paediatric patients with ALL.4 The association between MTHFD1 1958G>A polymorphism and hepatotoxicity grade ≥ 2 could not be assessed in the present study due to the low frequency of hepatotoxicity grade ≥ 2.