In humans, the circulating chemerin concentration is significantly elevated among individuals with obesity and/or T2D (173) and NAFLD (29), and the levels of chemerin correlate with levels of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-6 (30, 31). Here, RARRES2 is linked to obesity due to melanocortin 4 receptor deficiency.