The recently identified GB virus C is a flavivirus related to the hepatitis C virus. It appears quite prevalent in the general population and especially in individuals at risk of parenteral transmission. Many questions remain, most importantly the pathogenic role of the virus. It is unlikely that this virus has a major role in hepatic disease.
Goubau, P., & Liu, H. F. (1998). GB virus C: a novel pathogen or a curiosity for virologists? Acta Clinica Belgica (Multilingual Edition), 53(2), 100-104. https://hdl.handle.net/2078.5/135827 (Original work published 1998)