The OX40, that is, “tumor necrosis factor receptor superfamily, member 4” (CD134, TNFRSF4) and its ligand OX40L,” “tumor necrosis factor (ligand) superfamily, member 4” (OX40L, CD252, TNFSF4), are fundamental in augmenting the immune response against cancer cells. The gene discussed is TNFSF4; the disease is cancer.