PECAM1 and neoplasm: This was further emphasized by mRNA analysis of whole tumor preparations, where a significant elevation in hypoxia-related genes (i.e. Glut-1 (Slc2a1), Angpt2, Stc2, and Semaphorin B) could be seen coinciding with reduced CD31-staining (Fig. 3a and b; Additional file 8: Table S2).