PTK2 and cancer: Consistent with previous findings that FAK and mitogen-activated protein kinase (MAPK) signaling play essential roles in cancer cell proliferation and metastasis [16,17], FAK, JNK, p38, and ERK1/2 phosphorylation was significantly increased by serum stimulation in both cells, and BHMPS treatment markedly inhibited the phosphorylation of these molecules, especially FAK and JNK (Figure 2B).