Woodchuck secreted CTLA4, also known as Cytotoxic T-lymphocyte-associated protein 4 and CD152, with N-terminal Avi-TagTM fused to the Fc region of Human IgG1, a.a. 36-162 expressed in a HEK293 cell expression system. MW = 42 kDa (monomer). This protein runs at a higher MW by SDS-PAGE due to glycosylation.