HHLA2 and neoplasm: Univariate Cox proportional regression analysis identified various risk factors for OS in the training cohort, including tumor number, size, differentiation, MVI, AFP, GGT, CD34, CD68, CD66b, Treg/CD8, CCR4-T, CCL17-T, CCL17-I, HHLA-2, CD73-T, and CCR4 + CD73 + cells.