ALDH1A1 expression has been correlated with poor overall survival in a range of cancers, including leukemia, lung, liver, pancreatic, breast, colorectal and ovarian cancer.8 Resistance to chemotherapy represents a significant challenge in the treatment of ovarian cancer, with a high proportion of women ultimately succumbing to recurrent disease.9 Tumour recurrence arises from drug-resistant tumour cells able to repopulate the tumour niche and seed new lesions. Here, ALDH1A1 is linked to ovarian cancer.