SOX2 and central nervous system cancer: To elucidate, in which way the migratory behavior was compromised in the SOX2-knockdown cells, we focused on focal adhesion kinase (FAK), on its downstream signaling protein human enhancer of filamentation (HEF1/NEDD9) and metallo-matrixproteases which are essential for a proteolysis-dependent invasion and migration of glioma cells [30,31].