Authors' contributions
ELK carried out molecular genetics studies, quantitative RT-PCR, and dynamic bile collection for Figure 9. KL carried out molecular genetic studies and made the targeting construct. The knockout mice were isolated in the NM laboratory. HY performed Northern blotting. ELK, AK, EV and MHL performed Western blotting and immunohistochemistry experiments. AK and NL performed bile collection experiments and bile characterization for Figure 8. MA performed FPLC analysis. SS, AK and RK performed GC sterol analyses. JC assisted with dynamic bile collection and mouse surgery. ROE, AG, NM, GS and SBP were responsible for supervision, data analyses of experiments and for providing funding of these experiments. ELK and SBP wrote the paper.