To investigate the ability of aptamer conjugated nanocarriers, bearing a targeting ligand against EpCAM, to deliver the anti-cancer drugs, HT-29 (EpCAM+) and NIH/3T3 (EpCAM−) cells were treated with PEG-Au-NPs@5-FU, Apt-PEG-Au-NPs@5-FU and free 5-FU and monitored by flow cytometry and fluorescence microscopy. This evidence concerns the gene EPCAM and cancer.