TFII-I also known as GTF2I is a phosphoprotein containing six characteristic repeat motifs. TFII-I protein binds to the initiator element (Inr) and E-box element in promoters and functions as a regulator of transcription.TFII-I protein plays a crucial role in regulating gene expression, particularly in TATA-less promoters, which are essential for transcribing many genes that lack a traditional TATA box. This characteristic is particularly important as TATA-less promoters are often found in genes expressed in a tissue-specific manner or in response to specific signaling pathways. TFII-I not only binds to various core promoter elements, such as pyrimidine-rich initiator and E-box elements, but also activates c-fos transcription factor, a key player in MAP kinase signaling pathway.