TRAP100/MED24 is a component of the multisubunit mediator complex that functions as an interface between gene-specific transcription factors and the RNA Pol II/general transcription factor machinery. The mediator complex was first identified as a coactivator of the thyroid hormone receptor and has since been observed to function as a coactivator of a variety of transcription factors. TRAP100/MED24 associates with mediator subunit TRAP220. Both are essential to mouse development and play a role in androgen receptor-mediated transcription. Studies in zebrafish have shown that TRAP100/MED24 is also important to retinal development.