ESR1 and hepatocellular carcinoma: We compared the expression of estrogen receptor gene in eight microarray expression datasets of four tumors (Cervical cancer: GSE63514 and GSE63678; Colorectal cancer: GSE73360 and GSE74602; Cholangiocarcinoma: GSE76297; Hepatocellular cancer: GSE87630, GSE112790 and GSE121248).