MED4 (Mediator Complex Subunit 4) is a Protein Coding gene. Among its related pathways are Metabolism and Regulation of lipid metabolism by Peroxisome proliferator-activated receptor alpha (PPARalpha). MED4 encodes a component of the Mediator complex. The Mediator complex interacts with DNA-binding gene-specific transcription factors to modulate transcription by RNA polymerase II. Alternatively spliced transcript variants encoding multiple isoforms have been observed for MED4.