As vascular ERBB4 expression in GBM could make ERBB4 a viable target for anti-angiogenic therapy, we evaluated whether ERBB4-positive vessels in a tumor microenvironment can be regulated by anti-ERBB therapy, by using a subcutaneous alginate plug model of angiogenesis (Figure S8A–D). This evidence concerns the gene ERBB4 and glioblastoma.