FcγRIIB functions as an IgG transporter in the mammary gland

Proceedings of the National Academy of Sciences, Volume 123, Number 5, February 2026.
ImportanceThe acquisition of maternal IgG (immunoglobulin G) is essential for the early development of newborn immunity. Among the number of IgG Fc receptors expressed in placental mammals, FcRn (neonatal IgG Fc receptor) has already been recognized as the only…