ALDH1B1 is 75% identical to ALDH2, and is also located in mitochondria (Stagos et al., 2010, Jackson et al., 2011, Vasiliou et al., 2013, Stewart et al., 1995). It is expressed at much lower levels than ALDH2 (Figure 4). Both because of its lower expression and its much lower affinity for acetaldehyde (Table 3) ALDH1B1 does not normally play a large role in acetaldehyde oxidation. However, knocking out Aldh1b1 in mice led to a significant increase in blood acetaldehyde after ethanol consumption (Singh et al., 2015).
