RETN and obesity due to melanocortin 4 receptor deficiency: Luminex analysis showed that in the HFD-induced obesity mouse model, there was an obvious increase in serum proinflammation cytokines such as TNF-α, MCP-1, IL-12, IL-1β, IL-6, CCL3, CXCL16, and Resistin, which were further alleviated significantly in the CD226KO group (Fig. 4A).