Major pathogenetic factors which link obesity to metabolic diseases involve increasing levels of circulating free fatty acids, endoplasmic reticulum (ER) stress, altered levels of adipokines, decreased adiponectin, and infiltrating macrophage-derived cytokines, such as increased MCP-1, TNF-α, and IL-6 [147,148,149,150,151,152,153,154]. The gene discussed is ADIPOQ; the disease is obesity due to melanocortin 4 receptor deficiency.