Background: The TFIID complex is important for coordinating the pre-initiation complex and transcription by RNA Pol II. The complex contains the TFIID protein, TATA binding protein (TBP) and multiple TBP-associated factors (TAFs). TAF6 is also known as TAFII70 and is a TAF implicated in p53-mediated transcription. TAF6 exists as multiple splice variant isoforms and may play an important role in breast cancer cell growth.