CCNE1 and liver cancer: First, the expression of CCNE1 in human liver cancer was analyzed by using TCGA data on UALCAN (http://ualcan.path.uab.edu/cgibin/TCGAExResultNew2.pl?genenam=CCNE1&ctype=LIHC), and the results showed that the expression of CCNE1 in human liver cancer tissues was significantly higher than that in adjacent normal tissues (Additional file 1: Figure S2A).