CD274 and non-Hodgkin lymphoma: To the best of our knowledge, Zhao et al. [46] performed the first meta-analysis, which included 9 studies, to explore the relationship between PD-L1 overexpression and prognosis in NHL patients and concluded that PD-L1 overexpression has an association with poor prognosis in NHL and DLBCL but not with natural killer/T-cell (NK/T) lymphoma.