Immunostaining showed that the expression of Ki67 in xenograft tumours generated from HuR KO1 and HuR KO2 cells was significantly reduced compared with that in xenograft tumours generated from sgControl PC3 cells, indicating that the proliferation of PC3 cells was inhibited by HuR deficiency in vivo (Fig. 2C). This evidence concerns the gene MKI67 and neoplasm.