CD4 and cancer: Adding to TNFRSF4’s potential role as a prognostic indicator in cancer, the interaction between its produced protein OX40 and ligand OX40L has been proposed as a potential target for immunotherapy, as the resultant signals can promote survival of CD4+ and CD8+ T cells, sustain their anti-apoptotic protein expression and enhance cytokine production to augment tumour-specific T-cell response [48].