CLDN1 and synovial sarcoma: In labial salivary glands (LSGs) obtained from SS patients, the expression patterns and distributions of various TJ proteins, including ZO-1, occludin, and claudin-1, -3, and -4, are altered by focal pro-inflammatory cytokines.21 Similarly, in the submandibular glands (SMGs) of non-obese diabetic (NOD) mice, a recognized animal model for SS, there is an observed increase in the clearance of paracellular tracers, a widened acinar TJ zone, and aberrant expression profiles of multiple TJ proteins.