Schematic illustration of the mechanism of cell death induced by bendamustine. TNFRSF signaling generally provides survival signals (green and yellow arrows) to both lymphoma cells and T cells, but it is converted to death signals (red lightning bolts) after bendamustine treatment (left panels). Blockade of OX40L-OX40 signaling protects T cells under bendamustine treatment by preventing OX40-mediated death signals (right panels).