Univariate analysis showed that the depth of tumor invasion, lymph node metastasis, distant metastasis, level of serum carcinoembryonic antigen (CEA), level of serum carbohydrate antigen (CA) 19-9, and HHLA2 expression were significantly related to overall survival (P < 0.0001, P = 0.0001, P < 0.0001, P < 0.0001, P < 0.0001, and P = 0.0004, respectively) (Table 2). The gene discussed is HHLA2; the disease is neoplasm.