EGFR and glioblastoma: Using a panel of cultured cells, including serum-starved astrocytes derived from RasB8 mice as well as several GBM cell lines (including U87-EGFRvIII, with activated EGFR-ERK/Ras signaling) and HEK293 cells, we found that serum starvation and the consequent inhibition of cell proliferation correlated with increased CIC protein expression (Fig. 2a, b, Supplementary Figure 2A and B).