We correlated the expression of the 63 genes differentially expressed between CD44+ cancer cells and CD44+ normal tissue with clinical and pathological data, using the information from the MicMa breast cancer patients cohort database, which includes data on molecular expression and clinical information on 96 breast cancer patients followed up for 10 years (http://www.ncbi.nlm.nih.gov/geo, accession number GSE19425) (Figure 3). Here, CD44 is linked to cancer.