TGFB1 and hepatitis C virus infection: The statistical analysis for the forest plot in Figure 4 shows an RR of 0.76 (0.69, 0.85) for the significant versus nonsignificant impact of TGF-β1 polymorphism and levels on the incidence of hepatic cirrhosis and hepatitis C. The heterogeneity of this analysis was chi2 = 130.71, with df = 7 and P < 0.01, and I2 = 95%.