Although these results may indicate higher metastatic capacity of B16.F1 TNFR1-sufficient tumor cells, we could find no signs of macroscopic spontaneous metastasis in brain and lungs, even after 30 days of subcutaneous inoculation of B16.F1 in WT and TNFR1 KO mice (data not shown). This evidence concerns the gene TNFRSF1A and neoplasm.