Functions as a GC-rich promoter-specific transactivating transcription factor. Interacts with GTF2B, GTF2F2, RNA polymerase II and TBP. According to PubMed:12842993, it localizes to the cytoplasm. Widely expressed. Some isoforms may be specifically expressed in veins and arteries (at protein level). Isoform 4 is widely expressed. Isoform 1, isoform 2 and isoform 3 may be specifically expressed in vascular smooth muscle cells. Belongs to the vasculin family. Contaminating sequence. Sequence of unknown origin in the N-terminal part.