LPL and obesity due to melanocortin 4 receptor deficiency: The comparison between KK and KK-Ay mice indicates that suppression of the hepatic mTORC1/S6K pathway in KK-Ay mice restored obesity-related adipose LPL downregulation and serum TG elevation (Fig. 7l,m) to degrees similar to those in lean KK mice (Fig. 7l,m).