TNFRSF9 and myelodysplastic syndrome: OX40, Inducible T-cell COStimulator (ICOS) and 4-1BB+: Tumor protein 3 (TP53) MDS patients display reduced numbers of OX40+ cytotoxic T-cells and helper T-cells, as well as reduced ICOS+ and 4-1BB+ NK-cells [74].