Abstract: Objective To investigate the expression of YEATS Domain Containing 2（YEATS2） in hepatocellular carcinoma （HCC）and its relationship with prognosis. Methods A total of 112 cases of paraffin specimens of liver cancer and adjacent tissues surgically removed in our hospital from January 2010 to January 2014 were collected. Real-time PCR was used to determine the expression of YEATS2 mRNA in HCC tissues and adjacent tissues，Western blot and Immunohistochemical staining were used to detect the protein level of YEATS2，Immunofluorescence staining was used to detect the localization of YEATS2 in HCC tissues and the correlation between YEATS2 and clinicopathological characteristics and prognosis of HCC patients were analyzed，the results were verified by TCGA database. Results Real-time PCR results showed that the expression of YEATS2 mRNA in HCC tissues was up-regulated more significantly than that in adjacent tissues （P<0.001）. Western blot showed that the expression of YEATS2 was increased in approximately 66.67% （12/18）HCC tissues. Immunohistochemical staining founded that YEATS2 expression was up-regulated in 71.43%（80/112） HCC patients，and its expression was significantly correlated with TNM stage（P<0.001）. YEATS2 was mainly expressed in nucleus of hepatocellular carcinoma. Multivariable analysis showed that high expression of YEATS2 was an independent risk factor for poor prognosis of HCC patients（HR=2.204，95%CI：1.388-3.500，P=0.001）. The HCC cohort analysis in TCGA also showed that patients with high expression of YEATS2 had poorer OS （HR=1.751，95%CI：1.107-2.770，P=0.017）. Conclusion YEATS2 is highly expressed in HCC tissues and correlated with poor prognosis of HCC patients.

Key words: Hepatocellular carcinoma, YEATS2, Prognosis