MiR-19a was found to be the main oncogenic component of the miR-17-92 cluster by downregulating the tumor suppressor PTEN [28], [29]; it was overexpressed in a mouse model of human breast cancer bone metastasis [30] and induced enhanced neoangiogenesis by targeting the anti-angiogenic regulator thrombospondin-1 (Tsp-1) [31]. This evidence concerns the gene THBS1 and breast cancer.