As such, despite the basis of the study revolving around the theory that vascular disruption drives local tumour control, it cannot be ruled out that the enhancement effect could be a result of direct or indirect influences of fXRT+USMB to tumour cell interactions or, at the very least, acts independently of the ASMase-ceramide pathway in a fractionated radiation regimen. The gene discussed is SMPD1; the disease is neoplasm.