In vitro, PDT was performed on a subset of the available human cell lines, with EGFR driven U87 and U87vIII, cells representing PDGFR subtypes, and U373vIII, the patient-derived glioma stem cell line GSC-30 and the non-EGFR expressing GS2 cell line provided controls. The gene discussed is PDGFRB; the disease is glioma.