TAF9B is a TATA-box binding protein-associated factor essential for cell viability 1. As a component of transcriptional complexes including TFIID, TFTC, STAGA, and PCAF, TAF9B regulates RNA polymerase II-mediated transcription 1. Unlike its paralog TAF9, TAF9B has distinct roles in gene regulation, controlling a separate set of genes with minimal overlap 1. TAF9B stabilizes p53 and exhibits differential induction during apoptosis, suggesting specialized functions in apoptotic gene regulation 1. In osteosarcoma, TAF9B overexpression promotes proliferation and invasion while inhibiting apoptosis through Bcl-2/Bax regulation and AKT/mTOR pathway activation; miR-7-5p suppresses these pro-tumoral effects 2. TAF9B participates in a p53-regulatory feedback loop with sno-miR-28, where p53 represses TAF9B-targeting microRNAs 3. In doxorubicin-induced cardiotoxicity, miR-146a targeting TAF9B reduces apoptosis by destabilizing p53 4. Loss of heterozygosity in TAF9B is associated with metastasis-free survival in breast cancer, indicating prognostic significance 5. TAF9B dysregulation also occurs in osteoarthritis pathogenesis 6. These findings suggest TAF9B as a therapeutic target across multiple cancer and degenerative disease contexts.