May play a role in the ERK signaling pathway by inhibiting the dephosphorylation of ERK by phosphatase PP2A-PPP2R5C holoenzyme. Acts also as an ERK downstream effector mediating survival (By similarity). As a member of the NUPR1/RELB/IER3 survival pathway, may allow the development of pancreatic intraepithelial neoplasias. Interacts with the PPP2R5C-PP2A holoenzyme and ERK kinases; regulates ERK dephosphorylation. Expressed predominantly in the lung, testes and the uterus. By serum growth factors and TPA. Glycosylated. Belongs to the IER3 family.