TMEM173 acts as a facilitator of innate immune signaling. It is able to activate both NF-kappa-B and IRF3 transcription pathways to induce expression of type I interferon (IFN-alpha and IFN-beta) and exert a potent anti-viral state following expression. TMEM173 may be involved in translocon function, the translocon possibly being able to influence the induction of type I interferons.It also may be involved in transduction of apoptotic signals via its association with the major histocompatibility complex class II (MHC-II). TMEM173 mediates death signaling via activation of the extracellular signal-regulated kinase (ERK) pathway.