Transcription regulator that modulates expression mediated by transcription factors of the GATA family. Cofactor that acts via the formation of a heterodimer with transcription factors of the GATA family. Such heterodimer can both activate or repress transcriptional activity, depending on the cell and promoter context (By similarity). Interacts with the N-terminal zinc finger of gata1. Expressed at the lateral plate mesoderm. The CCHC FOG-type zinc fingers probably directly bind to GATA-type zinc fingers. The Tyr residue adjacent to the last Cys of the CCHC FOG-type zinc finger is probably essential for the interaction with GATA-type zinc fingers (By similarity). Belongs to the FOG (Friend of GATA) family.