That we find a differential degree of Mup transcript(s) enrichment in C57Bl/6J wild type and ob/ob mice when we use the Mup1 primer set vs. the Mup1/2 primer set suggests that within the Mup multigene family there are distinctions regarding the influence of obesity on the degree of differential expression of particular Mup transcript(s). Here, MUPP is linked to obesity due to melanocortin 4 receptor deficiency.