Concerning the inhibition of the tumorigenesis and metastasis of breast cancer, ISL can rectify the abnormal PI3K/AKT, NF-kB, and p38 signaling pathways in order to reduce the occurrence of metastasis through correcting the expression of MMP-2, MMP-7, MMP-9, VEGF, and HIF-1α [39,57,65,66,67]. This evidence concerns the gene MMP9 and breast cancer.