We generated 100 μm-thick slices of U87MG brain glioma xenografts isolated at either the early (9 days post-transplantation) or middle stages (26 days post-transplantation) of tumor progression (Fig. 7), and performed immunostaining for epidermal growth factor (EGFR), proto-oncogene c-Mer Proto Oncogene Tyrosine Kinase (MERTK), and lectin. The gene discussed is EGF; the disease is brain glioma.