The high CTSA protein expression of HCC patients was related to TNM staging (P = 0.024), serum AFP level (P = 0.001), tumor location (P = 0.037), tumor differentiation (P = 0.031), tumor recurrence (P = 0.013), and survival (P = 0.036), but not related to age, gender, tumor size, vascular invasion, and tumor encapsulation (Table 3). Here, AFP is linked to hepatocellular carcinoma.