sentences:  Two components of the CDK module (MED12 and MED13) are involved in the Wnt signaling pathway MED23 is involved in RAS/MAPK/ERK pathway This abbreviated review shows the versatility of individual mediator subunits, and leads to the idea that mediator is an end-point of signaling pathways.Involvement of mediator in various human diseases has been reviewed.Since inhibiting one interaction of a disease-causing signaling pathway with a subunit of mediator may not inhibit general transcription needed for normal function, mediator subunits are attractive candidates for therapeutic drugs.