ALDH1A1 and neoplasm: Accumulating evidence has demonstrated that Nrf2 can directly regulate the transcriptional expression of ALDH family molecules, and its high activity is a key driver for ALDH-positive tumor cells to maintain stem cell-like properties (Kim et al., 2018); Moreover, ALDH1A1’s catalytic activity and protein stability are highly dependent on reduced glutathione (GSH) to scavenge reactive oxygen species (ROS) generated during its metabolic reactions (Wang et al., 2017).