NTN1 and neoplasm: Different cell types in the tumor microenvironment in GBM such as glial cells (astrocytes and oligodendrocytes), microglia, infiltrating immune cells (monocytes, macrophages, and lymphocytes), EC, and pericytes can express Netrin-1 and its receptors [47,49,50,51,52,53,54,55,56,57,58] (Table 2).