LEP and obesity due to melanocortin 4 receptor deficiency: The proposed underlying mechanisms for the link between obesity and allergy include pro-inflammatory adipokines (leptin, IL-6, TNF-α) released from adipose tissue [133], pro-inflammatory Th1 cells and Th17 cells associated with adipose tissue from obese individuals [5], and the ILC2–eosinophil–macrophage axis [5] in adipose tissue.