CD44 and glioblastoma: To further confirm our observations, we measured PBX3 and mesenchymal markers mRNA levels in 45 GBM samples by qRT-PCR and observed high expression levels of N-cadherin, ZEB1, Slug and CD44 in GBMs with high PBX3 expression (n = 23) than those with low PBX3 expression (Additional file 1: Figure S1E-H).