PIK3R1 and obesity due to melanocortin 4 receptor deficiency: By intersecting our lists of genes across multiple analyses, we found 434 differentially expressed genes with expression levels correlated with body fat % in the CC that were associated with obesity traits in humans (Fig. 4C; see Supplementary Tables 7 and 8, Additional file 2), with three genes exclusively differentially expressed by diet, 369 genes exclusively differentially expressed by strain (e.g., Ide), and 62 genes differentially expressed by both diet and strain (e.g., Pik3r1).