MED26 is a core subunit of the Mediator complex, a coactivator essential for RNA polymerase II (RNA Pol II)-dependent transcription 1. As a component of the core Mediator (cMED), MED26 directly recruits RNA Pol II and promotes pre-initiation complex (PIC) formation at gene promoters 12. MED26 regulates the transition from transcription initiation to elongation by recruiting the super elongation complex (SEC) to polyadenylated genes and the little elongation complex (LEC) to non-polyadenylated genes 3. The N-terminal domain of MED26 mediates binding interactions with TATA-binding protein-associated factor 7 (TAF7) and EAF1, facilitating the initiation-elongation switch 4. MED26 function is negatively regulated by the CDK8 kinase module (CKM), which blocks RNA Pol II recruitment through an intrinsically disordered region in MED13 that occludes MED26 binding sites; nuclear receptor signaling repositions this inhibitory region to enable MED26-dependent RNA Pol II interaction 21. Genome-wide, MED26 primarily regulates transcriptional bursting frequency and functions as a critical node integrating gene regulatory networks 5. MED26 participates in organizing nuclear bodies including Cajal bodies and histone locus bodies to coordinate 3' RNA Pol II pausing and processing 3. In disease, MED26 has emerged as a candidate gene for Mendelian disorders 6, though further clinical characterization is needed.