Figure 2

Fibroblasts influence mammary epithelial cell growth. Colony-forming assays were performed with an increasing density of irradiated NIH 3T3 cells plated alongside a set density of prospectively fractionated human bipotent mammary progenitor cells (black; n = 6 patient samples), 184-hTERT-L9 cells (blue; n = 4) and MCF10A cells (red; n = 4). The whisker ends on the box plots denote the lowest and highest data within 1.5× the interquartile range of the lower and upper quartiles, respectively.