Semaphorin (Sema) family is originally defined as axonal guidance factors, which plays an important role in axon-directing of the nervous system. Subsequently, increasing studies have shown that Sema family is also involved in immune response, tumor angiogenesis and organogenesis. Sema3A is the earliest studied axonal guidance factor in the Sema family. In recent years, it has been found that Sema3A has also played an important role in the occurrence and development of tumors and autoimmune diseases (AD). However, whether Sema3A plays an inhibitory or facilitative role in tumorigenesis is still inconsistent. To elucidate the role of Sema3A in tumor immunity and autoimmune regulation is expected to provide new ideas for immunotherapy targeting Sema3A. Therefore, this article reviews the latest research progress on the structure and receptors of Sema3A, as well as role and mechanisms of Sema3A in neoplasms and AD.
