Figure 3: CD44 enriched as well as CD44 depleted human breast cancer cell populations are able to integrate and contribute their progeny to mixed mammary outgrowths. Immunocytochemical staining of mixed mammary outgrowths obtained from the inoculation of either CD44 enriched or CD44 depleted MDA-MB-231- GFP breast cancer cells (10K) and mouse mammary epithelial cells (50K) A, E) Human keratin 8 (green); B, F) human keratin 14 (green); C, G) mouse keratin 14 (red); D, H) human mitochondria (red). A-D) CD44 enriched; E-H) CD44 depleted. Scale bars = 10 μm. Figure from Rosenfield and Smith, 2013.