To confirm the in vivo roles of Mir20b in obesity model mice, we introduced Mir20b using an adenovirus-associated vector (AAV), referred to as AAV-Mir20b, into C57BL/6 mice that had been fed a normal chow diet (NCD) or a high-fat diet (HFD). This evidence concerns the gene MIR20B and obesity due to melanocortin 4 receptor deficiency.