The result indicates that both Slug expression and ERK phosphorylation were increased in MCF-7 and MDA-MB-231 cells with miR-665 overexpression and decreased in BC cells with less expression of miR-665 when compared with the corresponding control cells (Fig. 7b), suggesting that miR-665 promotes migration, invasion and metastasis via activating MEK pathway. The gene discussed is SNAI2; the disease is breast cancer.