ALDH2 and cancer: Several of these isoforms have been reported by other groups to be involved in ALDEFLUOR assay, namely ALDH1A1 (Jones et al. 1995), ALDH1A2 (Moreb et al. 2012), ALDH1A3 (Marcato et al. 2011b), and ALDH2 (Garaycoechea et al. 2012; Moreb et al. 2012), while the other five ones have seldom been described and their role in cancer have not yet been explored in detail.