Genes modulating 184-
-L9 co-culture growth also affect primary human mammary epithelial cell growth. Single-cell suspensions of dissociated human primary mammary cells were infected with individual short-hairpin RNA (shRNA) constructs targeting our screen-identified gene set prior to being plated in colony-forming assays. The fraction of surviving colonies after silencing of the target genes relative to a nontargeting shRNA control is plotted. Error bars represent 95% confidence intervals (n = 3 patient samples).