Novel ATP8B1 mutation in an adult male with progressive familial intrahepatic cholestasis

Figure 4 Expression pattern of the canalicular transporter bile salt export pump (rabbit anti-bile salt export pump polyclonal antibody, all images, × 400). A: Normal bile salt export pump (BSEP) staining in a control liver without cholestasis. Anti-BSEP antibody stains an orderly canalicular network; B: BSEP staining in liver tissue collected from the patient 13 years ago. BSEP is present only focally (arrows) and is both faint and patchy; C: BSEP staining in the recent sample of liver tissue BSEP expression is again faint and patchy; D: Canaliculi in negative control liver stained with phosphate-buffered saline.