TAF12 (TATA-box binding protein associated factor 12) is a crucial component of the general transcription machinery that functions within multiple transcriptional regulatory complexes. TAF12 is a core subunit of the TFIID complex, which plays a major role in RNA polymerase II-dependent transcription initiation by recognizing promoters and promoting pre-initiation complex assembly 1. The protein also participates in other transcriptional complexes including TFTC (TATA-binding protein-free TAF complex), PCAF histone acetylase complex, and STAGA transcription coactivator-HAT complex 2. TAF12 functions as a transcriptional coactivator through direct protein-protein interactions, notably with ATF7, where it potentiates ATF7-induced transcriptional activation and binds to vitamin D response elements on target promoters like CYP24A1 34. In disease contexts, TAF12 acts as an oncogene in multiple cancer types. It is upregulated in RAS-transformed colorectal cancer cells through ETS1-mediated transcriptional regulation and contributes to epithelial-to-mesenchymal transition by modulating E-cadherin expression 5. TAF12 has been identified as an oncogene in choroid plexus carcinoma and serves as a poor prognostic marker in glioma 67. These findings establish TAF12 as both a fundamental transcriptional regulator and a clinically relevant oncogene.