The TFIID basal transcription factor complex plays a major role in the initiation of RNA polymerase II (Pol II)-dependent transcription (PubMed:33795473). TFIID recognizes and binds promoters with or without a TATA box via its subunit TBP, a TATA-box-binding protein, and promotes assembly of the pre-initiation complex (PIC) (PubMed:33795473). The TFIID complex consists of TBP and TBP-associated factors (TAFs), including TAF1, TAF2, TAF3, TAF4, TAF5, TAF6, TAF7, TAF8, TAF9, TAF10, TAF11, TAF12 and TAF13 (PubMed:33795473). The TFIID complex structure can be divided into 3 modules TFIID-A, TFIID-B, and TFIID-C (PubMed:33795473). TAF8 is involved in forming the TFIID-B module, together with TAF5 (PubMed:33795473). Mediates both basal and activator-dependent transcription (PubMed:14580349). Plays a role in the differentiation of preadipocyte fibroblasts to adipocytes, however, does not seem to play a role in differentiation of myoblasts (PubMed:14580349). Required for the integration of TAF10 in the TAF complex (PubMed:14580349). May be important for survival of cells of the inner cell mass which constitute the pluripotent cell population of the early embryo (By similarity). {ECO:0000250|UniProtKB:Q9EQH4, ECO:0000269|PubMed:14580349, ECO:0000269|PubMed:33795473}. This is the function of ENSG00000137413 (TAF8, TATA-box binding protein associated factor 8).