PECAM1 and neoplasm: We further found that nintedanib treatment did not influence the number of CD31+ microvessel structures in this model (Supplementary Fig. 3), although it has been shown to possess marked antiangiogenic activity.22 Nintedanib treatment resulted in a marked delay in tumour growth (Fig. 1e) and significantly prolonged the survival of the model mice (Fig. 1f) compared with vehicle treatment.