Glioblastoma cancer stem cells--from concept to clinical application.

Ten years after the first description of cancer stem cells (CSCs) in glioblastoma (GBM), the initial concept of CSC has been challenged and our understanding of cellular heterogeneity within malignant brain tumors became more complex. The increasing knowledge on CSC also influences preclinical research and clinical practice. This review therefore describes current concepts and controversies on CSC in GBM and summarizes the recent progress how the CSC hypothesis is about to translate into preclinical and clinical application.