DKK3 and glioblastoma: To better investigate the way in which Wnt signaling modulate Dkk-3 protein and claudin-5 expression we examined the expression of Dkk-3 and claudin-5 in human GBM cell lines (U-138MG, A-172, LN-18 and LN-229), using NHA cells as control, by Western Blot analysis.