To this end, the EpCAM aptamer was linked to the PLK1-specific siRNA sense strand and annealed to the antisense strand (EpCAM-AsiC), showing that the conjugate selectively induced gene silencing in the target EpCAM expressing epithelial breast cancer cells and their stem cells, while sparing normal epithelial cells and surrounding stroma. This evidence concerns the gene EPCAM and breast carcinoma.