To that end, we stably infected three disparate cell lines, the non-tumorigenic MCF10a mammary epithelial cell line, T47D breast cancer line and the unrelated human embryonic kidney-293 line with lentivirus expressing a non-targeting control shRNA (shCon) or an anti-REST shRNA (shREST), which resulted in the robust knockdown of REST protein (Figure 1A). This evidence concerns the gene REST and breast cancer.