"Hepatitis C virus (HCV) infects an estimated 3% of humanity  and is a leading global cause of liver disease and liver cancer . Intervention is currently limited by the lack of a vaccine and of universally successful drug treatments. Although several next-generation drugs (e.g., direct-acting protease-inhibitors) are already improving outcomes, a number of factors will affect overall treatment success . Among these, viral genetic variation and the emergence of drug resistance are of major importance."
Via Ed Rybicki