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). Here, ACE2 is linked to primary biliary cholangitis.