Use

CD3 antigen is a marker of T‑cell lineage, first detectable in early thymocytes (cytoplasmic expression) and later on the membrane. It is the most specific T‑cell antibody, expressed in normal thymocytes, peripheral T‑cells, NK cells, and Purkinje cells of the cerebellum. In pathological contexts, CD3 immunohistochemistry (IHC) stains most T‑cell lymphomas, with only rare B‑cell lymphomas showing positivity.