We next explored the tumorigenic function of KDM5B with in vivo mouse model, utilizing xenografts implanted with EBV-positive epithelial tumor cells that had been genetically modified to either stably knock down or overexpress KDM5B. Notably, xenografts derived from KDM5B-knockdown cells exhibited significantly reduced growth, as evidenced by decreased tumor volume and weight (Fig. 4f–h), and corroborated by diminished Ki-67 staining, indicative of low cell proliferation (Supplementary Fig. 3h). This evidence concerns the gene MKI67 and neoplasm.