Regarding the tumor types and tumor histology, the unfavorable prognostic effect of PD-L2 was consistently significant both for OS and DFS/PFS in HCC, which has startling heterogeneity and lacks an efficient therapeutic approach (45, 46), suggesting that PD-L2 may serve as prognostic marker especially in HCC. The gene discussed is PDCD1LG2; the disease is neoplasm.