GATA1(Globin transcription factor 1) is a Cys2/Cys2 zinc finger DNA binding protein that is expressed primarily in erythroid, megakaryocytic, mast cells and eosinophilic cells. It belongs to the GATA family of transcription factors. GATA1 is a transcriptional activator which probably serves as a general switch factor for erythroid development. It binds to DNA sites with the consensus sequence [AT]GATA[AG] within regulatory regions of globin genes and of other genes expressed in erythroid cells. The protein also plays an important role in erythroid development by regulating the switch from fetal hemoglobin production to adult hemoglobin.