The cancer stem-like cell marker Lgr5 and differentiation marker CK18 were detected using RT-PCR in HGC-27 and MGC-803 cells; TRAF6 knockdown resulted in the downregulation of Lgr5 and upregulation of CK18 (Figures 4(a) and 4(b)). The gene discussed is LGR5; the disease is cancer.