As microvascular endothelial cells may exhibit the same genetic aberrations as tumour cells (Gunsilius, 2003; Hida et al, 2004; Streubel et al, 2004), we first analysed whether the tumour vasculature in ACN/neo and ACN/IFN-γ xenografts contained tumour-derived endothelial cells. Here, IFNG is linked to neoplasm.