In univariate analysis for OS in the training cohort, tumor multiplicity (P < 0.001), microvascular invasion (MVI) (P = 0.001), LN metastasis (P < 0.001), elevated serum CA19–9 level (P = 0.048), high HHLA2 expression (P = 0.004; Fig. 2a) and advanced AJCC 8th stage (P < 0.001) were found to have a significant correlation with unfavorable OS. Here, HHLA2 is linked to neoplasm.