ERBB4 and glioma: As shown in Figure 1A and Supplementary Table 1, glioma patients exhibited a significantly higher copy number of EGFR (6.53 vs. 1.91; P =0.01), HER2 (3.87 vs. 2.36; P =0.001), HER3 (4.21 vs. 2.09; P =0.01), and HER4 (4.43 vs. 1.98; P =0.01) than control subjects.