Recently, the use of new antiviral drugs (DAA) has shown a dramatic increase in sustained virological response. The Unit aimed to identify some predictors of response to DAA and of liver disease progression, both viral and host-related (variants of the cannabinoid receptor 2, CB2-63 and PNPLA3). Some virological studies, including ours, suggest the presence of minority natural variants within the viral HCV population as "quasispecies", which are resistant to DAA drugs. These data may have important clinical implications, especially for coinfected HIV / HCV patients who may have multiple genotypic/subtypic infections that can not be detected by the common methods available in the clinical practice. This study suggests that triple therapy with new DAAs may also be ineffective in individuals with mixed infections, as some of these molecules are genotypes/subtypes specific and the defined pangenotypic molecules are however less effective on some HCV genotypes. The unit collaborates with national and international networks (PITER, EuroSIDA, EUROSUPPORT, ICONA, COHERE, Regional Network for HCV therapy) and receives funding from pharmaceutical companies for the conduction of national and international phase II-IV treatment studies and from national ( ICONA) and international (EuroSIDA, EUROSUPPORT) agencies.