PECAM1 and neoplasm: Vascular examination by CD31 staining on xenograft sections did not show significant difference of the endothelial density between SR-DMSO tumour and SS-DMSO tumour; however, more larger vessels were visualised in SR-DMSO tumour than in SS-DMSO tumour and these larger vessels appeared to be less sensitive to sorafenib treatment (Fig. S3).