CES1 and congestive heart failure: In this study we therefore examined the influence of the above-mentioned genetic variations in CES1 on the plasma ATII/ATI ratio in ACEI-treated patients with CHF including nine of the SNPs in the upstream part of CES1A1, which form the so-called CES1Var. In addition, three selected CES1 variants that were not suspected to have a functional impact themselves were included as potential markers of causal genetic variants.