This volume is composed of chapters that review important fundamental aspects of HCV biology and disease pathogenesis including, for example, the discovery and identification of the HCV genome, early virus-cell interactions including identification of various cellular receptors, HCV gene expression studied using the HCV replicon system, identification and characterization of HCV structural- and non-structural HCV proteins, HCV replication in cultured cells, and host factors involved in viral replication. This volume also contains chapters dealing with immunity to HCV infection and pathogenesis. This is particularly important in understanding hepatitis C because HCV infection alone is not cell lytic. Mechanisms underlying the persistent nature of HCV infection are also discussed in these chapters. Many of the authors published articles that were listed among the “top 10 papers” published in the 24 years since HCV was discovered in 1989. Their citations are above 1,000 (Web of Science). The authors describe the background and significance of their contributions to the field in the context of findings from other research groups.