Abstract:The first human Pegivirus (HPgV-1) and the second human Pegivirus (HPgV-2) are the only two human Pegiviruses that have been identified until now. They share some common features including similar viral genome structure and low pathogenicity, while they also represent unique biological characteristics. HPgV-1 is called “good virus” because of its ability to slow down disease progression and reduce disease severity when co-infecting with HIV and Ebola virus. In addition, HPgV-1 was recently found to be related with lymphoma and neurological diseases. Therefore, HPgV-1 might be a possible breakthrough point in the treatment of refractory diseases caused by HIV and other viruses. HPgV-2 was firstly discovered from the plasma of a hepatitis C virus (HCV)-infected patient in 2015 and was found to always co-infect with HCV but hardly infect healthy people. However, the underlying mechanism of HPgV-2 and HCV co-infection remains to be elucidated. Distinct from most of RNA viruses, HPgV-2 exhibits low genomic diversity with high sequence identity and low intra-host variation, which give the implication of HPgV-2 as an excellent model for studying the mechanisms of viral genome variations. In conclusion, the human Pegiviruses are worthy of sustaining attention and study.