In this study, we demonstrate (1) Sch B significantly attenuates 4T1 metastasis thereby extending the survival time of mice; (2) Sch B attenuates 4T1 metastasis at the step of local invasion; and (3) Sch B inhibits EMT of 4T1 cells as well as primary human breast cancer cells. This evidence concerns the gene NF2 and breast carcinoma.