To explore the potential effect of HBO1-mediated H3K9la on the malignant behaviors of cancer cells, we constructed the 7 types of different HBO1-KO cell lines, including HeLa, HepG2 (hepatocellular carcinoma), U87MG (gliomas), KYSE-30 (esophageal squamous cell carcinoma), MDA-MB-231 (breast carcinoma), HCT116 (colon cancer), and H460 (non-small cell lung cancer). The gene discussed is KAT7; the disease is central nervous system cancer.