Biliary atresia (BA) causes neonatal cholestasis jaundice. The primary therapeutic treatment for BA is the Kasai portoenterostomy, a surgical procedure creating a new bile duct to restore bile flow. However, current diagnostic approaches for BA are imprecise and time-consuming, making early diagnosis crucial for successful treatment outcomes. The present study was aimed to analyze proteins from peripheral blood mononuclear cells (PBMCs) obtained from children with biliary atresia compared with healthy children as potential biomarkers for diagnostic tests.