It is interesting, however, that while we find differences (RRMS vs HC) in the levels of hormones (PTH and iFGF23) that regulate the activity of the enzymes 1-alpha hydroxylase and 24-hydroxylase, which respectively synthesise and degrade the potent vitamin D metabolite 1,25(OH)2D, others find differences between people with MS versus HC in the genes coding for these same enzymes (Pierrot-Deseilligny and Souberbielle 2017). This evidence concerns the gene PTH and myeloid sarcoma.