Moreover, immunofluorescent analysis of CD31 for blood vessel staining (Fig 5B) showed enlarged tumor blood vessels in mice that received the non‐targeted/AAVP‐Grp78‐HSVtk/GCV, while the tumor blood vessel size was slightly reduced in mice treated with either RGD4C/AAVP‐Grp78‐HSVtk/GCV or TMZ alone. This evidence concerns the gene PECAM1 and neoplasm.