PDCD1 and lymphoma: According to the data based on a total of 184 DLBCL biopsies, PD-1 (CD279) and PD-L1 (CD273, B7-DC) expressions (i.e., expressed on more than 5% of cells) on lymphoma cells were detected in 1.63% and 43.48% of patients, respectively, while their expressions on microenvironment cells were found in 11.41% and 26.09% of patients, respectively [45].