The CD25 (HI25a) antibody recognizes a 55 kDa type-I transmembrane glycoprotein known as the low-affinity receptor for IL-2 (IL-2R?). CD25 associates with CD122 (IL-2R(B),Porcine75) and the common ? Chain-CD132 (IL-2R?,Porcine64) to form the high-affinity IL-2R comple, Xenopus/Amphibian,. CD25 antigen is e, Xenopus/Amphibian,pressed on activated T and B lymphocytes, activated macrophages, and adult T-cell leukemia (ATL) cells, but is absent from resting T and B cells. CD25 antigen density is altered by treatment with PHA, ConA and CD3 antibody.