However, ALDH1+ T-ICs were more frequently detected in the ‘triple-negative’ (HER2-, oestrogen-, and progesterone receptor-negative) basal-like-subtype BC than in luminal BC (Charafe-Jauffret et al, 2009), suggesting that T-ICs may differ with the subtype of BC. Here, ALDH1A1 is linked to breast cancer.