Various studies have reported that high ALDH1A1 expression correlates with decreased overall survival (OS) in OC patients [47,48,49], reduced progression-free survival (PFS) [50], lower response to chemotherapy [50], and an increased number of ALDH1A1+ cells observed in ovarian tumors after CIS/PAC combined chemotherapy [51]. This evidence concerns the gene ALDH1A1 and in situ carcinoma.