IFN gamma receptor beta is part of the receptor for interferon gamma. This class II cytokine receptor pairs with CDw119 to form the IFN gamma receptor and is an integral part of the IFN gamma signal transduction pathway. CDw119 serves as the IFN gamma binding chain and associates with the IFN gamma beta chain which is required for receptor signaling. The extracellular portion of both the IFN gamma receptor alpha and beta chains must be species matched. The IFN gamma receptor beta chain is expressed on T and B cells, NK cells, monocytes/ macrophages, and fibroblasts.