ADH7 (σ-ADH or μ-ADH; Table 1), is the only member of the ADH family that is not expressed in liver (Figure 2). It has a high turnover number, and its high Km suggests it will be most active when ethanol concentrations are high, as they are during ethanol consumption in the esophagus (where its level of expression is affected by 62 eQTLs) and stomach, precisely its locations. A small study showed a significant contribution of ADH7 to first pass metabolism, particularly after low concentrations of oral ethanol (Dohmen et al., 1996).
