Mice with a deficiency of either tumor necrosis factor (TNF)-α, a master proinflammatory cytokine, or C-C motif chemokine ligand 2 (CCL2), a proinflammatory chemokine, were refractory to the development of malignant tumors in the classical two-stage skin carcinogenesis model [6]. The gene discussed is TNF; the disease is neoplasm.