On the other hand, epidermal fatty-acid binding protein [64], matrix metalloprotease (MMP) 2, MMP9, 8-hydroxy-2′-deoxyguanosine (8-OHdG), and 4-hydroxy-2-nonenal (4-HNE) are elevated in SS tear fluid [63]. The gene discussed is MMP9; the disease is synovial sarcoma.