INS and obesity due to melanocortin 4 receptor deficiency: The recently discovered adipokine chemerin65,66 increases insulin sensitivity in 3T3-L1 adipocytes67 and is essential for normal adipocyte differentiation.65,66,68 However, it has also been shown to lower glucose tolerance in murine models of obesity/diabetes69 and to cause insulin resistance in human skeletal muscle cells, where it was also observed to be pro-inflammatory.70 Consequently adipose tissue secretes both pro- and anti-inflammatory cytokines which modulate metabolism by altering insulin resistance.