In basal-like tumors, CD24+ corresponds to CD44– cells, because no CD24 expression is seen in these cases. (A) The Shannon index, H, indicating diversity within tumor cell subpopulations and tumors. For each tumor, 100 different cells for each of the 4 different types (IDC CD24+, IDC CD44+, DCIS CD24+, and DCIS CD44+) were analyzed, and their Shannon indices are depicted in dark blue, dark red, light blue, and light red, respectively. Higher score indicates higher diversity. Basal-like tumors are all uniformly highly diverse for 8q24, whereas a subset of HER2+ and luminal A tumors show a lower degree of diversity. (B) Whittaker plots (rank-abundance plots) depicting the abundance of unique cancer cells.