Objectives To investigate the expressions and significance of E2F1, ID1, and Bax protein in gallbladder adenocarcinoma tissues. MethodsThe expressions of E2F1, ID1, and Bax protein in 70 cases of gallbladder adenocarcinoma, 20 cases of high level intraepithelial neoplasia, 30 cases of low level intraepithelial neoplasia, and 20 cases of cholecystitis tissues were tested by using immunohistochemical method. ResultsThe positive expression rates of E2F1, ID1, and Bax protein in gallbladder adenocarcinoma was 84.3%, 70.0%, and 25.7%, respectively; the positive expression rates in high level intraepithelial neoplasia was 75.0%, 65.0%, and 55.0%, respectively; the positive expression rates in low level intraepithelial neoplasia was 16.7%, 23.3%, and 56.7%, respectively; and the positive expression rates in cholecystitis tissues was 10.0%, 20.0%, and 75%, respectively.The positive expression rates of E2F1 and ID1 protein in gallbladder adenocarcinoma were significantly higher than those intraepithelial neoplasia and cholecystitis tissues (P < 0.05), but the positive expression rate of Bax protein in gallbladder adenocarcinoma was lower (P < 0.05).The expressions of E2F1 and ID1 protein were significantly correlated with clinical Nevin staging of gallbladder adenocarcinoma (P < 0.05), but not correlated with the gallbladder adenocarcinoma differentiation degree (P > 0.05).The expression of Bax protein was related to the gallbladder adenocarcinoma differentiation degree (P < 0.05), but not correlated with clinical Nevin staging (P > 0.05).The expression of E2F1 protein was negatively correlated with expression of Bax protein (r=-0.375, P < 0.05), ID1 protein expression has nothing to do with the protein expression of Bax protein (P > 0.05).The expression of E2F1 protein was positively correlated with ID1 protein (r=7.031, P < 0.05). ConclusionsThe E2F1, ID1, and Bax may play an important role in the generation and development of the gallbladder adenocarcinoma.The combined detection of E2F1, ID1, and Bax have important guiding significance for auxiliary diagnosis and clinical staging of gallbladder adenocarcinoma.