Pterostilbene has been revealed to inhibit PI3K/Akt activation in breast cancer to suppress the heregulin-β1/HER-2-modulated invasive and aggressive phenotype of breast cancer cells [16], [36], [37], and reduced matrix metalloproteinase 9 (MMP) expression, which is an enzyme implicated in micrometastasis [16]. This evidence concerns the gene MMP9 and breast cancer.