CD4 and infection: The HCV RNA negative strand, representing virus genome replicative intermediate, viral proteins and virus sequences distinct from those occurring in the liver have been identified in PBMC, T and B lymphocytes, CD4+ and CD8+ T cell subsets, and in monocytes from patients with chronic hepatitis C (CHC) [20], [21], [30]–[35] and in persistent low-level infection continuing after clinically apparent sustained virological response to interferon (IFN) or IFN-ribavirin (IFN-RBV) therapy for CHC [21], [24], [34], [36]–[39].