MMP9 and hepatocellular carcinoma: Multivariate Cox regression analysis of the expression levels of MIR4435-2HG, MMP9 and DUXAP8 showed that MIR4435-2HG and DUXAP8 were reliable prognostic indicators in HCC patients (P  <  0.05) (Fig. 5a).Based on the correlation coefficient between the expression of these two genes, a risk model was constructed: risk score  =  (1.37 × expression value of DUXAP8 +  0.0896 × expression value of MIR4435-2HG) (Fig. 5b).