They showed that a single intravenous injection of ESTA at a dose of 100 μg prevented the formation of lung metastasis of CD44-positive breast cancer cells intravenously injected in mice, both in a syngeneic (murine 4T1 cells) and xenogeneic (human MDA-MB-231 cells) model of breast cancer metastasis, without a relocation of metastases formation to a distinct site from lung upon aptamer treatment [114]. This evidence concerns the gene CD44 and breast cancer.