The proportions of CD44+/high/CD24−/low cell populations across the PMC42 cell lines were compared with five other breast cancer cell lines (MCF-7, T47D, MDA-MB-468, MDA-MB-231 and SUM-159) and the expression of these surface markers was simultaneously assessed by FACS analysis (Figure 2A,B). This evidence concerns the gene CD44 and breast cancer.