CSRP3 and obesity due to melanocortin 4 receptor deficiency: Genes associated with muscle development and differentiations were up-regulated whereas genes involved in lipid transport were down-regulated (Fig. 6C, Table 2); for example, Csrp3 (cysteine and glycine-rich protein 3), one of the genes increased in βL group, is known to enhance skelectal myogenesis [20] and serine prepetidase inhibitor 1b and 1d (Serpina 1b and 1d) which are down-regulated and known to prevent obesity and insulin resistance [21].