MMP9 and hepatocellular carcinoma: HCC cells incubated with CoCl2 and treated with ginsenoside CK not only downregulated the HIF-1α-targeted proteins but also reversed the expression level of the hypoxia-induced EMT markers E-cadherin, N-cadherin, Vimentin, Snail and matrix metalloproteinases (MMP2 and MMP9) (Figure 6B,D).