Numb phenotype is autonomous to the epithelium. (A) Images of mammary gland wholemounts of control (Ad-GFP) and Numb-deficient (Ad-Cre-GFP) mammary fat pad transplants. (B) Fluorescence images of transplanted mammary glands immunostained for Numb (red) and E-cadherin (green). (C) Scatter plot of the total area of ductal coverage of fat pad transplants. (D) Fluorescence images of mammary transplants immunostained for CK8 and SMA to show luminal and myoepithelial cells, respectively. (E) Scatter plot of the total number of end buds from transplant outgrowths. (F) Scatter plot of cleaved-Caspase-3-positive cells from transplant outgrowths. n=24–25 ducts from eight to ten glands for each group. (G) Scatter plot of Ki67-positive cells from transplant outgrowths. n=34–43 ducts from eight to ten glands for each group. (H) Scatter plot showing the relative luminal cell density (number of cells/unit length). (I) Scatter plot showing the relative myoepithelial cell density. n=8–10 glands for each group (C,E). n=19–21 ducts from eight to ten glands for each group (H,I). Error bars=s.e.m. Scale bars: B, 2000 μm; C, 20 μm; D, 20 μm. Unpaired t-test; two-tailed: ***P<0.0005, *P<0.05, ns, not significant.