As shown in Table 1, exposure to exogenous Sema3A (300 ng/ml) reduced the directed migration of the osteoblast-like cell MC3T3 and the human osteosarcoma cell lines MG-63, MNNG/HOS (p < 0.01), KHOS and Saos-2 (p < 0.05). The gene discussed is SEMA3A; the disease is osteosarcoma.