PROM1 and lung cancer: Levina et al. characterized drug-selected H460 human lung cancer cells and showed that these cells have characteristics of lung CICs including (1) sphere formation and self-renewal capacity; (2) an undifferentiated phenotype with an ability to differentiate; (3) expression of the SP, CD133, embryonic stem cell markers, and growth factor and chemokines receptors; and (4) a high tumorigenic and metastatic potential [18].