PTK2 and hepatocellular carcinoma: In our previous studies it was shown that CD147 might promote HCC metastasis in multiple ways: by inducing matrix metalloproteinases (MMPs); by disrupting the HCC microenvironment [10]; by enhancing expression of βig-h3 [11]; and by regulating downstream metastasis-related genes, such as FAK, Girdin, Src and signal transducer and activator of transcription 3 (STAT3) [12,13].