IL2RG and neoplasm: Immunofluorescence analysis of tumor vessels shows off a remarkable property that distinguishes RCC-41-PDX-1/CD132+ from RCC-41-PDX-2 xenografts: in all PDX-2 xenografts, vessels are entirely of murine origin as shown by EM counts using hCD31 and mCD34 mAbs proved to be rigorously species-specific in a previous study [47].