MTHFR and male infertility: In humans, a number of studies have pointed out that impairment of the MTHFR gene can contribute to disease, including male infertility (Stangler Herodež et al., 2013; Tara et al., 2015; Coppedè et al., 2016, 2019; Lévesque et al., 2016; Asim et al., 2017).