AGO2 and primary biliary cholangitis: Step-down expression of miR-223-3p and miR-21-5p in peripheral blood B cells has signaled histological progression of PBC from stage I to stage III (204), and decreased levels of the molecules involved in the biogenesis of miRNAs (prolyl 4-hydroxylase subunit alpha 1 and Argonaute 2) have suggested a widespread disruption of the homeostatic network in a murine model of PBC (61).