Evidence for post-translational processing of vascular endothelial (VE)-cadherin in brain tumors: towards a candidate biomarker by Vilgrain, I, Sidibé, A, Polena, H, Cand, F, Mannic, T, Arboleas, M, Boccard, S, Baudet, A, Gulino-Debrac, D, Bouillet, L, Quesada, J, Mendoza, C, Lebas, J, Pelletier, L, Berger, F