Anti-IER3 antibodies are used in the immunodetection of the protein immediate early response 3. In humans, the canonical protein has a reported length of 156 amino acid residues and a mass of 16.9 kDa. Its subcellular localization is in the membrane. It is notably widely expressed in many tissue types. A member of the IER3 protein family, IER3 is believed to play a role in the ERK signaling pathway by inhibiting the dephosphorylation of ERK by phosphatase PP2A-PPP2R5C holoenzyme. Post-translational modifications have been described, including glycosylation and phosphorylation. Synonyms for this target antigen include DIF2, GLY96, IEX-1, IEX-1L, IEX1, PRG1, radiation-inducible immediate-early gene IEX-1, and DIF-2. IER3 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.