DUSP6 and glioblastoma: CIC was found to be expressed in several GBM and primary brain tumor-initiating cell (BTIC) lines (Fig. 5a, b) despite exhibiting increased expression of CIC target genes downstream of MAPK (ETV1/4/5, DUSP6, SPRY4; Additional file 6: Figure S5A, B), compared to NHA cells.