CD177 and primary biliary cholangitis: Therefore, HT-29 human colon carcinoma cells expressing the hmAchR M3 receptor (proven by Western blotting; data not shown) were fixed on cover slides and stained with sera from PBC patients (representative example given in Figure 1, lane A), or control sera IgG fractions from healthy donors (Figure 1, lane B) as well as a commercially available polyclonal antibody to the hmAchR M3 (Figure 1, lanes A+B, column 2); as a control for cell surface receptor staining, a Na+/K+-ATPase-specific antibody was used (Figure 1, lane C, column 3).