Additional studies have reported that ALDH1A1, ALDH7A1, ALDH2 and/or ALDH1A2 are responsible for driving Aldefluor® activity in other tumor types [32,33,34], indicating that the ALDH isoform(s) responsible for Aldefluor® activity may be tumor-specific. Here, ALDH7A1 is linked to neoplasm.