Could play a role in regulating gene activity in the proliferative and/or differentiative pathways induced by NGF. May be an autocrine factor that attenuates or amplifies the initial ligand-induced signal. Interacts with PSIP1/LEDGF. By mitogens such as TPA in 373 cells and by nerve growth factor in PC12 pheochromocytoma cells. Belongs to the IFRD family. Was originally thought to be interferon beta-2.