To date, some of the most potent PTK6 inhibitors, causing significant repression of breast cancer cell migration and invasion, are marine natural products such as the derivatives of the marine Triterpene Sipholenols: 4β-O-benzyl sipholenol A and 4β-O-benzyl-19,20-anhydrosipholenol A [105]. The gene discussed is PTK6; the disease is breast cancer.