TLR9 and sclerosing cholangitis: Because EGR1[23, 24] as well as toll‐like receptor 9 (TLR9)[25]–related pro‐inflammatory pathways are induced via potential toxic BAs such as CDCA and TCA, we explored next whether these inflammatory key players are implicated in the inflammatory liver injury seen in the Mdr2−/− mouse model of sclerosing cholangitis.