STAT3 and Obesity: In summary, we found that: 1) EPO facilitates energy expenditure by increasing classical BAT mass; 2) EPO stimulates EpoR/STAT3 and β-adrenergic receptor/Mef2c/miR-133 pathways, resulting in enhancement of PRDM16 of classical BAT; 3) EPO promoted secretion of classical BAT’s derived-FGF21; and 4) EPO ameliorated obesity and glucose homeostasis in high-fat diet-induced obese mice.