What are markers for breast cancer stem cells ?

Breast cancer stem cells were firstly discovered by Al-Hajj et al. (2003). Many scientists interested in targeting them as an important solution to “remove” the root of breast cancer. However, more and more publications showed that breast cancer stem cells are the heterogenous population that expression of some markers can be different between them. Particularly, some different markers were considered as markers of breast cancer stem cells. Therefore, what are gold standards of these cells? In this publication, we discussed some conflicts about markers of breast cancer stem cells and suggested some gold standards for breast cancer stem cells.