OXT and immunoglobulin G4-related sclerosing disease: The KEGG pathway analysis identified the pathways whose genes from the salivary gland tissues of IgG4-RD patients were differentially methylated: “calcium signaling pathway,” “cAMP signaling pathway,” “MAPK signaling pathway,” “oxytocin signaling pathway,” “Rap1 signaling pathway,” “Hippo signaling pathway,” “VEGF signaling pathway,” and “cGMP-PKG signaling pathway” (Fig. 4D).