Title: Clinical features and biomarker research advances in immunoglobulin 4-related digestive system disorders. This paper provides a comprehensive narrative review of immunoglobulin G4-related digestive system disorders (IgG4-DSD), with particular emphasis on clinical manifestations, immunopathogenesis, and emerging biomarkers. The topic is timely and relevant to the readership of the World Journal of Gastroenterology, especially with the increasing recognition of IgG4-RD as a critical differential diagnosis for pancreatobiliary malignancies and other gastrointestinal inflammatory conditions. The authors included a statement regarding the AI contribution: During the preparation of this work, the authors used ChatGPT in order to improve the language. After using this tool, the authors reviewed and edited the content as needed and took full responsibility for the publication's content.