IGF1R and lipodystrophy: Mice with an inducible knockout of the insulin receptor in adipocytes (Ai-IRKO) and inducible double knockout of both IR and IGF1 receptor (IGF1R) in adipocytes (Ai-DKO) using tamoxifen-inducible adiponectin-CreERT2 mice exhibit rapid development of lipodystrophy, with almost completely brown and white adipocyte loss, and severe metabolic syndrome15.