METRNL (Meteorin Like) is a secreted adipokine from white adipose tissues with diverse roles in lipid metabolism, skeletal muscle and or myocardium repair, inflammation, and immunology. It is involved in regulating energy expenditure and glucose homeostasis, and it promotes the browning of white adipose tissue, which increases energy expenditure. METRNL Isoform 2 is new adipokine with 229 amino acids .