EGFR+/CD133+ cells, which constitute a population of GICs with a high degree of self‐renewal and tumor‐initiating ability (Mazzoleni et al, 2010; Emlet et al, 2014), were sorted from primary patient‐derived glioblastoma samples and transduced with a GFP‐luciferase construct prior to injection into mice brains for further bioluminescence imaging. The gene discussed is EGFR; the disease is glioblastoma.