DUOX2 and primary biliary cholangitis: Interestingly, RNAscope and multiplex IF analyses of liver sections displayed that the numbers of DUOX2+ACE2+ small cholangiocytes in small bile ducts were dramatically reduced in PBC patients, compared to control patients (Fig. 3b–e, Supplementary Figs. 12 and 13, and Supplementary Table 9).