CD47 and glioblastoma: In addition, an increase in CD47 expression in U87 human GBM cells was also observed by ectopically expressing an activated EGFRvIII mutant, which is frequently detected in human GBM (Figure 2B).[8] Pretreatment of U251 human GBM (Figure 2C) and CT‐2A mouse glioma (Figure S2C, Supporting Information) cells with the EGFR inhibitors afatinib, AZD9291, or AZD3759 blocked EGF‐induced CD47 expression.