B and T lymphocyte attenuator (BTLA) is a member of the CD28 Ig superfamily of inhibitory co-receptors, along with CTLA-4 and PD-1. However, unlike CTLA-4 and PD-1, BTLA does not interact with B7-Ig family receptors. Rather, it is engaged by herpesvirus entry mediator (HVEM), a member of the TNF receptor superfamily, leading to an inhibited immune response. It also plays a role in immune tolerance. BTLA is expressed on most CD4 and CD8 T cells, B cells, macrophages, dentritic cells, and NK cell. Primary antibodies are available purified, or with a selection of fluorescent CF® Dyes and other labels. CF® Dyes offer exceptional brightness and photostability. Note: Conjugates of blue fluorescent dyes like CF®405S and CF®405M are not recommended for detecting low abundance targets, because blue dyes have lower fluorescence and can give higher non-specific background than other dye colors.