CD44 and breast cancer: To understand the regulatory roles of miRNAs in the function of breast CSC, ESA+CD44+CD24−lin− CSC and ESA+CD44−CD24+lin− non-CSC tumor cells were sorted from six freshly surgical breast cancer tissue samples and the profile of the Wnt/β-catenin signal-related miRNA expression in these cells were characterized by miRNA microarray (Figure 1A).