It was discovered, using U87 model cell lines and GBM patient-derived cells, that paracrine interactions between the subpopulations expressing activating mutations (EGFRvIII) and subpopulations harboring epidermal growth factor receptor amplification (EGFRwt) play a significant role in the diffuse architectures of GBM tumors. The gene discussed is EGFR; the disease is glioblastoma.