The results from our study and An et al. [27] suggest that Gnpat may not be a genetic modifier in HFE-hemochromatosis, however, this study examined the effect of heterozygosity of Gnpat, and not the effect of the GNPAT p.D519G variant believed to be associated with iron overload in HFE HH patients, and the possibility of this variant having an effect on HFE function cannot be completely ruled out based on the present study. Here, GNPAT is linked to Tangier disease.