Thus anti-4-1BB has no direct effect on the tumor and anti-4-1BB therapy can be effective if either the transferred T cells or the host cells express 4-1BB, implying that 4-1BB on the transferred T cells or on host cells is sufficient for anti-4-1BB to contribute to tumor control in the adoptive immunotherapy model. This evidence concerns the gene TNFRSF9 and neoplasm.