TGFB1 and hepatitis C virus infection: TS=("Transforming Growth Factor beta1" OR "TGF-beta1") AND TS=("Polymorphism" OR "SNP" OR "Genetic Variation") AND TS=("Hepatitis C" OR "HCV") AND TS=("Cirrhosis" OR "Liver Cirrhosis" OR "Liver Fibrosis" OR "Hepatic Fibrosis" OR "Hepatic Cirrhosis")