Ref: AP10094C – Clone: 4C9 – Host: Mouse – Method: P,F – Format: Concentrated

SKU: AP10094C Category: Tag:



CD25 is the alpha chain of the IL-2 receptor. It is a Type I transmembrane protein present on activated T-cells, activated B-cells, some thymocytes, myeloid precursors, and oligodendrocytes that associates with CD122 to form a heterodimer that can act as a high-affinity receptor for IL-2. It is expressed in most B-cell neoplasms, some Acute Non-lymphocytic Leukemias, and Neuroblastomas.

Expression of CD25 is a reliable diagnostic tool for distinguishing neoplastic mast-cell aggregates from reactive proliferations, and has, therefore, recently become a minor criterion for the diagnosis of Systemic Mastocytosis (SM). Anti-CD25 antibodies have also been useful in identifying mast cells in skin biopsies in the setting of Urticaria Pigmentosa, which is predictive of Systemic Mastocytosis. Quantitation of regulatory T-cells (Treg) in the setting of hepatocellular carcinoma has been used as an independent predictive factor for tumor recurrence after hepatic resection for HCC. Also, the percentage of tumor-infiltrating CD25+FOXP3+ regulatory T-cells among tumor cells, inside tumor parenchyma and at its periphery are significantly higher in recurrent Cutaneous Melanoma than in Non-recurrent Melanoma.

Clone: 4C9

Isotype: IgG2b

Immunogen: Recombinant protein corresponding to the external domain of the Interleukin-2 Receptor molecule.

Staining pattern: Cell membrane.

Positive control: Tissue sample from tonsil.


This antibody is designed for the specific localization of human CD25 using IHC techniques in formalin-fixed, paraffin-embedded tissue sections.