Abstract: The relationship between neuronal guidance factor and tumor is getting more and more attention. Semaphorin 3A(SEMA 3A) is the first one that studied as neuronal guidance factor in the family of Semaphorins.With the further research,it is fined that SEMA 3A also plays an important role in apoptosis,cell migration,tumor growth and immunoregulation.Therefore,it is considered that SEMA 3A is a new breakthrough of oncotherapy.This article reviews current knowledge on structure and mechanism of SEMA 3A, as well as its research status,focusing in the its “Promotion effect” and “Inhibiting effect” in cancer.

Key words: Semaphorin 3A, Neuropilin-1, plexin-A1, cancer