Members of the TNF receptor family, such as OX40 and 4-1BB, are costimulatory molecules that can be triggered to enhance anti-tumor activity.14 15 OX40 and 4-1BB expression is induced after antigen-priming and triggering their signaling pathways results in the potentiation of T cell and NK functions. Here, TNFRSF9 is linked to neoplasm.