The fact that HRG as a single treatment regimen could inhibit development of malignant gliomas and completely suppress glioblastoma development is encouraging and stimulates further studies using HRG alone and in combination with cytotoxic drugs and receptor tyrosine kinase (RTK) inhibitors, including VEGF inhibitors, to treat experimental glioma of all grades. This evidence concerns the gene NTRK1 and malignant glioma.