Autoimmune Hepatitis (AIH) and Primary Biliary Cholangitis (PBC) are autoimmune diseases that target the liver in which the immune system produces an inappropriate response to self-antigens resulting in inflammation, damage, and dysfunction of hepatic tissues. Despite progress in the understanding of the etiopathogenesis and in the diagnostic and therapeutic approach of these diseases, critical issues remain concerning the early diagnosis of affected individuals. The present study aims to detect and characterize by a gel-based bottom-up proteomic approach the acid-insoluble fraction of salivary proteome from patients affected by AIH and PBC with respect to healthy controls (HCs). The study was performed on the salivary acid-insoluble proteins after in-gel digestion starting from: i) the entire SDS-PAGE lane; ii) a portion of the SDS-PAGE at lowest molecular weight (MW </= 25 kDa).