Syncytin-B (Synb)

This endogenous retroviral envelope protein has retained its original fusogenic properties (PubMed:15644441, PubMed:18077339, PubMed:22032925, PubMed:27589388). Together with Syna, participates in trophoblast fusion and the formation of a syncytium through placenta morphogenesis (PubMed:22032925).

Synb is specially involved in formation of syncytiotrophoblast layer II (SynT-II) (PubMed:22032925). Promotes myoblast fusion, and might play a role in regeneration of damaged muscle tissue in males (PubMed:27589388).