PECAM1 and neoplasm: Tumours from mice treated with a single dose of erlotinib (60 mg/kg) 5 days after a single dose of bevacizumab (5 mg/kg) or 5 days after a single dose of human IgG (5 mg/kg) (n = 5 for each time point in each treatment group) (Table 1) were sectioned and stained with mouse CD31 to evaluate microvessel density.