TOE1 is a 510 amino acid long protein that belongs to the CAF1 family. It is a downstream target of EGR-1 and plays an important role mediating the inhibitory growth effect of EGR-1. EGR-1 directly binds the TOE1 promoter region and activates its expression. TOE1 induces the expression of TGF∫ and p21 and plays a role in cell cycle regulation and the inhibition of cell growth. The activity and nucleolar localization of TOE1 correlates with a G2 cell cycle phase delay which is likely due to an increased expression of p21. In addition, TOE1 may function via an interaction with p53 and possible modification to its activity. TOE1 is expressed at various levels in all adult tissues and specifically localizes to the nuclear speckles.