Human secreted programmedcell death 1 (PD-1), also known as PDCD1,SLEB2, CD279 and HPD-L, GenBankAccession No. NM_005018, a.a. 25-167,with C-terminal FLAG-Avi-His-tags, MW=20kDa, expressed in a HEK293 cellexpression system. The protein isenzymatically biotinylated using AviTag™technology. This protein runs at a higherM.W. by SDS-PAGE due to glycosylation.