Transcription factor (PubMed:9748269, PubMed:10207080). Activates the epsilon- and gamma-globin gene promoters and, to a much lower degree, the beta-globin gene and represses promoters containing SP1-like binding inhibiting cell growth (PubMed:9748269, PubMed:10207080, PubMed:16131492). Represses transcription of SMAD7 which enhances TGF-beta signaling (By similarity). Induces apoptosis (By similarity). Interacts with SIN3A. Ubiquitous. Higher expression in erythroid cells. By TGFB1. The disease is caused by variants affecting the gene represented in this entry. Belongs to the Sp1 C2H2-type zinc-finger protein family. PubMed:11087666 sequence was originally thought to originate from mouse.