Schematic representation of different clinical and virological subsets of mixed cryoglobulinemia (MC) syndrome. 1) 'essential' MC (EMC); 2) and 3) 'essential' MC and HCV-associated MC syndrome in the setting of definite autoimmune-lymphoproliferative disorders (ALD), such as autoimmune hepatitis, Sjögren's syndrome or B-cell lymphomas; 4) the most frequent subset of HCV-associated MC syndrome; 5) MC associated with other infectious agents such as hepatitis B virus (HBV). (modified from [12, 13]: Ferri C et al, B-cells and mixed cryoglobulinemia. Autoimm Rev 2007, 7: 114–20; Mascia MT et al, Non HCV-related mixed cryoglobulinemia. Dig Liver Dis 2007, 39: S61–4.).