CD25n

CD25n is a term encountered in some immunology literature, but it does not have a widely accepted, standardized definition. In the absence of a clear, universally agreed meaning, CD25n is typically interpreted only within the context of the specific study or dataset in which it appears. Possible interpretations include designation of a CD25-negative (CD25–) subset within a population, reference to a nonfunctional or low-expressing form of the IL-2 receptor alpha chain, or the labeling of a particular transcript or isoform identified in a niche experiment. Because definitions can vary by author, researchers should consult the original source to understand what CD25n denotes in that work.

CD25 itself refers to the alpha chain of the interleukin-2 receptor (IL-2Rα), encoded by the IL2RA gene. In humans, CD25 forms part of the high-affinity IL-2 receptor along with IL-2Rβ and the common γ chain, and it plays a central role in T cell activation, proliferation, and regulatory T cell (Treg) function. CD25 is commonly used as a marker for activated T cells and is a defining feature of natural and induced Tregs (CD4+ CD25+ FOXP3+). Therapeutically, anti-CD25 antibodies have been explored in transplantation and autoimmunity, reflecting the receptor’s importance in modulating IL-2 signaling.

In summary, CD25n lacks a standardized definition and should be interpreted with attention to the specific context and definitions provided in the source material.