IL4 and obesity due to melanocortin 4 receptor deficiency: A clinical study revealed that obesity was firmly connected with various proinflammatory cytokines, such as interleukins (ILs: IL-5, -10, -12, and -13), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α), and obese patients displayed elevated plasma levels of IL-4, -10, and -13 [9].