PTK2B and cancer: In our previous study, a variety of bromophenols (Figure 1) isolated from various marine algae, which exhibited excellent anticancer activity against A549, BGC-823, MCF-7, B16-BL6, HT-1080, A2780, Bel7402 and HCT-8 human cancer cell lines, could be used as potent antitumor agents for PTK over-expression of c-kit and is considered as part of a new therapeutic strategy for treatment of cancer [6].