Enhanced ALDH1A1 expression due to DDB2 silencing-induced transcription de-repression plays a critical role in this process, and ALDH1A1 inhibition can block the non-CSC-to-CSC conversion, limit the CSC subpopulation, and halt the tumor regrowth in DDB2-downregulated ovarian cancer cells. This evidence concerns the gene ALDH1A1 and neoplasm.