CLDN4 and synovial sarcoma: Specifically, the mRNA levels of tricellulin (MARVELD2), ZO-1 (TJP1), occludin (OCLN), ZO-3 (TJP3), claudin-3 (CLDN3), claudin-4 (CLDN4), and junctional adhesion molecule 3 (JAM3) were markedly lower in PGs and LSGs from SS patients (Fig. 1b).