IL1B and obesity due to melanocortin 4 receptor deficiency: Experimental results showed a synergistic effect of HFD-induced obesity with neuroinflammation developed by stress, demonstrated with overexpressed IL-1β, IL-6, and TNFα levels in the hippocampus compared to alone HFD or mild stress treatment, which associates with an increase in depression-like behavior in rats (Wang et al. 2022).