EGFR and glioblastoma: Changes in E-, N- and VE-cadherins, VCAM-1 and EGFR were analyzed by immunohistochemical reactions, Western blot and ddPCR methods in U-87 MG cells and GBM spheroids consisting of U-87 MG glioblastoma cells, HMEC-1 endothelial cells and macrophages;