Activation of the innate immune system via Toll-like receptor 4 (TLR4) by LPS triggers the expression of proinflammatory cytokines, fostering low-grade systemic inflammation associated with insulin resistance, hyperglycemia, and hyperinsulinemia, especially observed in individuals with obesity and type 2 diabetes (47, 48). The gene discussed is TLR4; the disease is obesity due to melanocortin 4 receptor deficiency.