ALDH1A1 and ovarian cancer: Recent studies additionally reported that a phenotype of CD44+CD24+Epcam+ is enriched for ovarian CICs [106], and aldehyde dehydrogenase-1A1(ALDH1A1)-positive cells are a population with properties of ovarian CICs, which are associated with chemoresistance, and down-regulation of ALDH1A can resensitize chemotherapy in ovarian cancer [107].