ALDH1B1 and neoplasm: To investigate how ALDH1B1 promotes tumor cell survival in confining spaces, we depleted ALDH1B1 in A549, H1299 cells, or H460 cells and rescued the cells with wild-type ALDH1B1 (WT) or ALDH1B1 enzymatic-dead (ED) mutant, which indeed had much lower activity than WT (Supplementary Fig. 3a–d).