Cox proportional hazards regression analysis indicated that NOX4 expression (p < 0.001), age (p = 0.026), sex (p = 0.036), number of tumors (p = 0.001), vascular invasion (p = 0.006), median differentiation grade (p = 0.038), and low differentiation grade (p = 0.001) were significantly associated with OS in HCC (Table 2). Here, NOX4 is linked to hepatocellular carcinoma.