Additionally, lapatinib, another EGFR inhibitor that has been shown to be escpecially potent in GBM tumors18, effectively reduced pEGFR levels (Fig. S4D) when used at non-killing concentrations (Fig. S4A), but failed to induce the formation of multicellular clusters (Fig. S4E,F). The gene discussed is EGFR; the disease is glioblastoma.