IL6 and obesity due to melanocortin 4 receptor deficiency: Adipose tissue, endothelial cells (vascular stroma), fibroblasts, macrophages, monocytes, and lymphocytes secrete IL6 contributing to acute phase reactions, chronic inflammatory processes, and homeostatic energy regulation, influencing obesity and insulin resistance (Stȩpień et al., 2014; Han et al., 2020).