A number of studies showed that DKK-1 induces apoptosis and inhibits tumor growth [15-17] DKK-1 expression in primary medulloblastoma cells is significantly down-regulated relative to normal cerebellum and transfection of a DKK-1 gene construct into D283 cell line suppresses medulloblastoma tumor growth [18]. The gene discussed is DKK1; the disease is neoplasm.