Secondly, SEMA3A secreted from tumor cells reduces the proliferation of recruited T-cells and antagonizes the synthesis of cytokines such as IL-2, IL-4, IL-10 and IFNγ in vitro (Catalano et al., 2006) The inhibitory effect of SEMA3A on T-cells are mediated by the activation of the member of RAS oncogene family Rap1, which in turn, inhibits the phosphorylation of MAP kinase-ERK kinase (MEK) and the mitogen-activated protein kinase (ERK1/2) (Catalano et al., 2006). The gene discussed is SEMA3A; the disease is neoplasm.