ETS1, a 441aa protein, is a member of DNA-binding ETS protein family. It is a multifunctional protein consisting of an N-terminal pointed domain, a central transactivation domain and 2 auto inhibitory domains flanked on both sides of conserved C-terminal Ets domain. It interacts with factors including PEBP2alphaA, p300/CBP and mediates transactivation of Osteopontin, Presenilin-1, Stromelysin and Collagenase. It is activated by Ras/MAPK signaling and its expression is up-regulated in resting T-cells. Its activity is modulated by various factors including AP-1, Sp-1, c-myb and MafB. Sp100 activates ETS1 in nuclear bodies. It interacts with EAP1/Daxx and causes repression of MMP1 and BCL2 transactivation. It interacts with STAT6 and modulates Socs-1 expression induced by IL-4. It interacts with GATA3 and positively regulates Tax-1 dependent IL-5 expression.