MMP9 and hepatocellular carcinoma: Generally, PIM2 up-regulation enhanced HCC cells’ ability to proliferate and to tolerate apoptosis through elevating the expression of CCND1 and Survivin, these are important for the initial stage of HCC tumorigenesis; PIM2 overexpression upregulated HIF1α and VEGF and enhanced angiogenesis, a rate limiting factor of HCC progression, which is critical for the progression of HCC; furthermore, PIM2 upregulation could elevate the expression of MMP9 and enhance HCC cells’ metastatic ability, which is pivotal for the development of advanced stage HCC.