ALDH1A1 and ovarian cancer: In order to evaluate the association HIF‐1α or HIF‐2α expression with stem cells markers in clinical ovarian cancer patients, we first used the Cancer Genome Atlas (TCGA) database to analyze the relationship between mRNA expression of HIF‐1A or EPAS1 and ALDH1A1, a CSC marker, in 379 ovarian cancer cases.