SMPD1 and neoplasm: The current studies that show large SDRT-induced radiosensitization of tumor response in the absence of normal tissue response add support for the concept that timed delivery of antiangiogenic drugs to derepress ASMase-ceramide signaling in combination with PMDS might make it possible to cure even those tumors adjacent to OARs with low thresholds for radiation toxicity, a concept we intend to test clinically in the near future.