ADAM21 and hepatocellular carcinoma: In an analysis of HCC clinical specimens, ADAM21 positivity was associated with vascular invasion, large tumor size, high histological grade, and low OS and RFS, and in a multivariate analysis, it was an independent risk factor for OS (hazard ratio = 2.778, P = 0.003) and RFS (hazard ratio = 2.473, P = 0.001) [87].