EGFR and central nervous system cancer: As expected, the expression of EGFR was significantly higher in the glioma cell lines U87MG (unpaired Student's t-test, ***P < 0.0001) and U251 (unpaired Student's t-test, ***P < 0.0001) than in the normal HA cell line (Figure 2A, 2B), which was in line with the previous studies showing that EGFR was highly expressed in glioma cells 48, 49.