Pepaj et al. (2015) used a proteomic approach to show that 1,25-dihydroxyvitamin D3 treatment induces overexpression of GDAP1 in a rat pancreatic beta-1 cell line. Thus, 1,25-vitamin D3 could potentially play a role in CMT, through the up-regulation of the GDAP1 gene. Further studies are required to assess the impact of 1,25-dihydroxyvitamin D3 supplementation on the expression of the GDAP1 gene in CMT patients and its clinical impact. The gene discussed is GDAP1; the disease is Charcot-Marie-Tooth disease.