The hallmark gene set analysis using GSEA (Fig. 6G) showed that gene sets such as APOPTOSIS (genes mediating programmed cell death (apoptosis) by activation of caspases), INFLAMMATORY RESPONSE (genes defining inflammatory response), IL2-STAT5 SIGNALING (genes up-regulated by STAT5 in response to IL2 stimulation), and HYPOXIA (genes up-regulated in response to low oxygen levels (hypoxia)) were activated in the PBMCs of individuals with obesity compared to lean individuals, where as the P53 PATHWAY (genes involved in p53 pathways and networks) gene set was suppressed. Here, IL2 is linked to obesity due to melanocortin 4 receptor deficiency.