Ovarian cancer cells pre-treated with growing doses of platinum show increased number of ALDH1+ cellsHGSOC cells showing ALDH1+/EGFR+ phenotype are correlated with the worse prognosisHigh expression of ALDH1+ cells correlates with chemoresistanceCD44+/CD133+/ALDH1A1+ cells are increased in recurrent tumorsExpression of CD133+/ALDH1+ correlates with shorter PFS and OS in HGSOC. Here, ALDH1A1 is linked to ovarian cancer.