E2F3 and cholangiocarcinoma: Exosomes secreted by TAM contained highly expressed hsa_circ_0020256, which enters cholangiocarcinoma (CCA) cells and causes upregulation of hsa_circ_0020256, and further upregulates E2F3 by sponging miR-432-5p, thus enhancing the proliferation, invasion and metastasis of CCA cells (285).