CXCR4 and cancer: Jung et al. demonstrated that CXCR4+ cancer stem-like cells drive therapy resistance in NSCLC and that CXCR4 inhibition (AMD3100, siRNA) suppressed sphere formation and tumorigenicity, suggesting that targeting CXCR4+ NSCLC stem-like cells could overcome drug resistance and enhance radiotherapy response (Jung et al., 2013).