Flow-cytometry analysis of DCIS.COM and SUM-225. Cells grown in 2D were stained by using the indicated anti-human antibodies to the surface markers, CD44/CD24, CD49f/CD24, and CD49f/MUC-1. The antibodies were directly conjugated, except for MUC-1, which was conjugated by using an anti-mouse FITC antibody. The histograms show expression levels for the indicated surface markers. The expression level is arbitrarily designated as low (lo) if the log10 of median fluorescence intensity (FI) is between about 0 and 2, medium (med) if the FI is between about 2.1 and 3.6, and high (hi) if the FI is higher than about 3.7.