Immune cells can also directly influence the phenotype and function of tumor vessels through various cytokines, such as cytokines that inhibit tumor angiogenesis (interferon-α, interleukin-12, interleukin-18 or tumor necrosis factor) and chemokines (CXCL9, CXCL10 or CCL21) (54–56). The gene discussed is CCL21; the disease is neoplasm.