NTRK1 and glioblastoma: Examining genetic alterations of major GBM driver genes in the two TCGA GBM tumors with the NTRK1 fusion (Figure S5), we found that the NTRK1 fusion accompanied mild amplification (<2 folds) of EGFR. As the amplified EGFR may mediate resistance to NTRK1 inhibition therapy [26], combinational use of NTRK1 and EGFR inhibitors may need to be explored.