Description
Plexin-B1 is related to axon guidance in the central nervous system. The Sema4D function is also widely detected in the immune system and was found to be the first semaphorin expressed on the surface of many types of immune cells. In the immune system, CD72 is a low-affinity receptor for Sema4D, and studies have shown that Sema4D can not only regulate T cell activation, but also participate in the regulation of B cell survival and differentiation. In the immune system, soluble fragments containing extracellular domains produced by proteolytic cleavage can regulate many physiological functions of Sema4D. Sema4D is also associated with tumorigenesis because studies have confirmed that it is overexpressed in various types of solid tumor cells. To some extent, the role of Sema4D in tumorigenesis is related to its ability to cause tumor angiogenesis, cell invasion, and immunosuppression by enhancing bone marrow-derived suppressor cell function.