Description: This 22F6 monoclonal antibody reacts with human, mouse and canine Helios. Helios is a zinc-finger transcription factor first identified for its similarity to Ikaros. It is expressed in hematopoietic stem cells in both the embryo and adult mice. While the highest expression is found in regulatory T cells, Helios is not expressed in mature B cells, dendritic cells or myeloid cells. Helios can form a homodimer as well as heterodimerize with other Ikaros family members to regulate transcription. Eight isoforms of Helios exist, some of which possess a dominant-negative function that has also been found to be upregulated in lymphoid malignancies, including T-acute lymphoblastic leukemia.