HOXA5 and obesity due to melanocortin 4 receptor deficiency: Besides its pathophysiological role, the methylation changes at the HOXA5 locus may also act as biomarkers to predict the risk of obesity and type 2 diabetes (T2D), in line with the current view that methylation changes detected in bloodborne DNA may represent a mark for other tissues more directly implicated in disease pathogenesis [17].