VEGFA and neoplasm: After exposure to NMU, Copenhagen rats developed multiple microscopic nodules regardless of the treatment regime employed, and all these nodules were associated with the major blood vessels of the mammary glands.[23] When the expression of vascular endothelial growth factor (VEGF) was examined immunohistochemically,[2] VEGF was almost exclusively restricted to the tumor cells and no non-neoplastic breast tissue expressed VEGF.