Transcription factors implicated in P-TEFb recruitment and function. Activators may recruit P-TEFb directly (e.g. Tat, c-Myc), or indirectly through binding to Brd4. P-TEFb recruitment is also linked to H3S10P, which can be mediated by MSK1,2 or Pim1, which can be recruited through c-Myc:TRRAP complexes. TRRAP is a frequent target of DNA activators and associates with HAT complexes that acetylate chromatin and stabilize binding of Brd4. P-TEFb functionally cooperates with proteins like SKIP to activate transcription and RNAPII CTD phosphorylation links elongation with downstream events required for gene expression.