The heterogeneity test showed a high level of heterogeneity at 94% and 95% for OR and RR, respectively, but the overall effect was significant with P < 0.01 for both measures. According to the results obtained, the authors concluded that TGF-β1 polymorphism and its associated levels should be taken into account while developing preventive and therapeutic approaches for hepatic cirrhosis and hepatitis C. This evidence concerns the gene TGFB1 and hepatitis C virus infection.