ELL2 (elongation factor for RNA polymerase II 2) is a transcriptional elongation factor that functions as a component of the super elongation complex (SEC), which increases RNA polymerase II transcriptional efficiency by suppressing polymerase pausing 1. ELL2 is stoichiometrically limiting in SEC formation and is regulated at the protein level through ubiquitin-mediated degradation by the E3 ligase Siah1 1. Beyond transcription elongation, ELL2 exhibits tumor suppressor properties in prostate cancer, where it is frequently downregulated and androgen-responsive 2. ELL2 physically interacts with the retinoblastoma (RB) protein, and their combined loss enhances prostate cancer cell proliferation, migration, and invasion 3. Additionally, ELL2 plays a critical role in DNA repair by facilitating non-homologous end joining (NHEJ) through direct interactions with Ku70 and Ku80 proteins, promoting their recruitment to DNA damage sites 4. The protein is stabilized by EAF2, which inhibits its polyubiquitination 2. Genetic variants in ELL2 associate with multiple myeloma susceptibility and influence immunoglobulin levels, with the risk allele showing reduced ELL2 expression in plasma cells 56. ELL2 variants also modulate IgA glycosylation patterns 7.