The present invention relates to complexes of the FOXC2 protein with other proteins, in particular complexes of FOXC2 with proteins designated p621, NOLP, HSC71, FTP3, CLH1, and Kinase A Anchor Protein 84/149 (AKAP). The protein complexes can be used in methods of identifying agents useful for the treatment of medical conditions that can be treated by modulated FOXC2 activity, such as obesity, hypertriglyceridemia, diet-induced insulin resistance, and/or type 2 diabetes.