Plays a role in the regulation of lipogenesis, especially in lactating mammary gland. Important for the biosynthesis of triglycerides with medium-length fatty acid chains. May modulate lipogenesis by interacting with MID1IP1 and preventing its interaction with ACACA. May function as transcriptional coactivator. May modulate the transcription factor activity of THRB (By similarity). Homodimer. Heterodimer with MID1IP1. Interacts with THRB and PLAGL1 (By similarity). Highly expressed in liver, lactating mammary gland, epididymal, retroperitoneal and brown fat. Mainly expressed in tissues that synthesize triglycerides. The mRNA levels in rat liver are up-regulated in response to thyroid hormone (T3) and a carbohydrate-rich diet. Up-regulated in liver at the time of weaning, when pups switch from a high-fat milk diet to having to synthesize their own fatty acids. Down-regulated by fasting. Levels of mRNA increase within 20 minutes of T3 administration. Belongs to the SPOT14 family.