Li X, Lewis MT, Huang J et al.
Baylor College of Medicine, Houston, TX, USA.
J Natl Cancer Inst 2008;100:672–9.
Editor’s note: In this study, the authors tested the hypothesis that the breast cancer stem cells (SCs) or tumor-initiating cells (TICs) are insensitive to conventional chemotherapy and therefore responsible for cancer relapse. If this were the case then the relative number of TICs within the residue tumor would be higher after therapy. However, if all the cancer cells acquired resistance, resulting in reduced sensitivity to therapy over time, then the proportion of cells with tumorigenic properties would be the same before and after therapy.