Similarities/differences between normal and malignant breast epithelial stem/progenitor subpopulations. The diagram summarizes the similarities and differences between the different Ep-CAM/CD49f populations. Each epithelial population was further fractionated into subpopulations based on the expression of other stem/progenitor cell makers. The three Ep-CAM/CD49f epithelial cell populations of the normal breast (A, B, and C), and their subpopulations, on top are compared with their malignant counterpart below. ♣Percentage of each epithelial population (average ± SEM, n = 9 normal & n = 12 for breast cancer).**NA = not done due to very low cell yield *Mo/CFC = mammosphere/colony forming cells. For mammosphere and colony forming ability, √√√ = high, √√ = medium, √ = low, X = none.