PROM1 and squamous cell lung carcinoma: We isolated human CSCs (CD133+/EpCAM+) and non-CSCs (CD133−/EpCAM+) from a squamous cell lung cancer xenograft using fluorescence-activated cell sorting (FACS) and respectively collected a total of 9.19×104 (3.4%) and 2.18×106 (96.6%) live cells corresponding to the two subpopulations (Figure 2).