Effect of the FGG H2 genotype on plasma APC resistance.FGG H2 genotype and thrombin generation at 6.8 pM TF in the absence and presence of 10 nM APC were determined in 188 FV Leiden heterozygotes. The ETP_−APC (A) and the ETP_+APC (B) were plotted as a function of the FGG H2 genotype. Hx indicates any other FGG haplotype except H2. The P values refer to the regression coefficients of the ETP_−APC and ETP_+APC vs FGG H2 genotype.