ALDH1A1 and neoplasm: Consistent with SAE2 knockdown, IHC staining of tumours in the shSAE2 group showed reduced level of SAE2, as well as reduced level of the CSC markers ALDH1A1 (an isoform believed to be critical for ALDH activity in CSCs30) and CD44, relative to shCtrl cells (Fig. 2b).