Human B- and T-lymphocyte attenuator BTLA, also known as CD272, GenBank Accession No. NM_181780, a.a. 31-150, with C-terminal Avi-Tag fused to the Fc region of Human IgG1, expressed in a HEK293 cell expression system. MW = 42 kDa (monomer). This protein is enzymatically biotinylated using Avi-TagTM technology.