Using protein–protein interaction (PPI) network analysis, we found that the rDEGs involved in the lipid metabolism process formed a complex network centered on glucocorticoid receptor (Nr3c1) and insulin receptor substrate 1 (Irs1) (Figure 7B), reinforcing the fact that FGF21 LKO abrogates OVX-induced central obesity via modulating both GC/GR signaling and insulin signaling. The gene discussed is IRS1; the disease is Abdominal obesity.