Human secreted Programmed Cell Death 1_x000D_(PD-1)-Fc fusion protein, also known as_x000D_CD279, PDCD1, and SLEB2, GenBank_x000D_Accession No. NM_014143, amino acids_x000D_25-167 with an I126A mutation, fused at the_x000D_C-terminus with the Fc portion of human_x000D_IgG1, and C-terminal AviTag™, expressed_x000D_in a HEK293 cell expression system and_x000D_enzymatically biotin-labeled using AviTag™_x000D_technology. MW = 44.5 kDa. This protein_x000D_runs at a higher MW by SDS-PAGE due to_x000D_glycosylation.