SREBF1 and obesity due to melanocortin 4 receptor deficiency: We further examined whether the diminished binding of CtBP2 observed in obesity is specific to FoxO1 and SREBP1 by detecting the interaction of CtBP2 with a known partner, zinc-finger protein FOG family member 1 (ZFPM1), that was again decreased in the liver of obesity (~96%, Supplementary Fig. 4f).