A small subset (~5%) of T cells in which the T-cell receptor has γ and δ subunits (unlike the more common α and β). They are found in the gut mucosa, within the intraepithelial lymphocyte population, and also in epithelial sites. Their exact role is unclear although they may be an important first-line defence. There is considerable diversity in the receptor subunits and most have neither CD4 nor CD8.
Subjects: Medicine and Health.