ERBB2 and neoplasm: For the model of xenograft tumor in nude mice, the tumor weight in the control group and the HER2-interfered group was 0.12 ± 0.04 g and 0.32 ± 0.06 g, respectively (p = 0.0192, Figures 4D,E), which demonstrated that the GCSCs have a relatively higher tumorigenicity in nude mice when the expression of HER2 was down-regulated.