These likely represent astrocytic end‐feet characteristic of a healthy blood‐brain barrier.[37, 85] In glioblastoma, GFAP is expressed by both reactive astrocytes and neoplastic glial cells of astrocytic morphology,[37, 39] but such structures are absent near MVP basement membranes (Figure 1C; Figure S1D, Supporting Information). The gene discussed is GFAP; the disease is glioblastoma.