The HLA-DQ (HI118) antibody recognizes the HLA DQ antigen, a HLA class II antigen that is mainly expressed on specialized antigen-presenting cells (APC), dendritic cells, B-cells, monocytes, macrophages and activated T-cells. HLA class II antigens present exogenous-derived antigens to T-cell receptors (TCR) on CD4+ T lymphocytes. Both chains in HLA DQ are polymorphic. HLA DQ is highly expressed in the thymic cortex and is expressed after DR and DP during hematopoietic progenitor cell development. This antibody recognizes DQ6 and DQ8 but not DQ2.