Furthermore, the immunosuppressive tumor microenvironment, characterized by high numbers of immunosuppressive cells, such as M2 macrophages and regulatory T-cells, and high levels of immune-suppressive cytokines, such as vascular endothelial growth factor (VEGF), hinders the maturation of DCs and causes the absence of activated dendritic cells. The gene discussed is VEGFA; the disease is neoplasm.