Karakus et al. and Naghibalhossaini et al. reported that subjects carrying the 677 T allele had an increased susceptibility to BD and MS [32, 47], whereas Chorąży et al. and Koubaa et al. reported that the MTHFR 677 C/T was not a risk factor for BD and MS [34, 54]. Here, MTHFR is linked to myeloid sarcoma.