miR-320 has been reported to be decreased in breast tumor tissue and downregulation of miR-320 - through loss of phosphatase and tensin homolog (PTEN) -has been shown to promote tumor proliferation and invasiveness in mouse models; expression of miR-320 distinguished human normal breast stroma from tumor stroma and was correlated with recurrence [49]. This evidence concerns the gene PTEN and breast neoplasm.