MMP2 and hepatocellular carcinoma: MAP kinase 4 (MKK4)/c-Jun N-terminal kinase (JNK) signalling, which can be activated by LPS treatment, significantly enhanced the production of matrix metallopeptidase 2 (MMP2), MMP9, IL-6, and TNF-α and the invasiveness of HCC cells (Dong et al., 2015).