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 (By similarity). May function as transcriptional coactivator. May modulate the transcription factor activity of THRB. {ECO:0000250, ECO:0000269|PubMed:17418816, ECO:0000269|PubMed:18299245}. This is the function of ENSG00000151365 (THRSP, thyroid hormone responsive).