S100A9 and biliary atresia: Based on the role of inflammation/immunity in the pathogenesis of biliary atresia, we ranked the genes based on the levels of expression (Fig 6B), and developed primers to quantify hepatic mRNA expression for the top 6 genes (Igj, Ltf, Mmp7, Lcn2, S100a8 and S100a9); the levels of expression of these genes increased 9.55–45.09 fold over controls.