ALDH1A1 and breast cancer: Consistent with our results, Lee and colleges studied the impact of BCS cells on 92 breast cancer patients after chemotherapy and found that cases with increased BC cells or aldehyde dehydrogenase 1+ (ALDH1+) phenotypes (a reliable marker for breast cancer stem cells) had significantly shorter disease-free survival time, and they concluded that their study provided the clinical evidence that the BCS cells in breast cancer are chemoresistant and are associated with disease progression, emphasising the need for targeting BCS cells in breast cancer therapies [29].