In another lung metastasis mouse model, renal adenocarcinoma (Renca) inoculation into TNFR1-deficient mice displayed spontaneous regression of metastasis foci as compared with wild-type (WT) mice, indicating that signal transduction via TNFR1 supports tumor neovascularization and promotes lung metastasis [21]. The gene discussed is TNFRSF1A; the disease is papillary renal cell carcinoma.