Patients with SS-HCV had a higher frequency of combined cryoglobulin-related markers (cryoglobulins, RF, and low C4) and a lower frequency of isolated cryoglobulins compared with SS patients without HCV infection (47 % vs. 18 % and 15 % vs. 34 %, respectively, P=0.019). The gene discussed is C4A; the disease is synovial sarcoma.