CNR2 and alcohol abuse: Several other factors have been found to be associated with CHC progression and severity, such as the duration of HCV infection, coinfection with hepatitis B virus (HBV), insulin resistance, diabetes, high body mass index (BMI), immunosuppression of different etiology, alcohol abuse, drug addiction, interleukin-28B polymorphism and the cannabinoid receptor 2 (CB2)-63 variants [22–28].