 Furthermore, CD69 is also known to be upregulated by NF-κB signaling at the onset of an immune response.A prolonged immune response is then maintained by the non-canonical NF-κB pathway, which in turn is associated with Treg differentiation.In addition to Treg differentiation, CD69 is a common marker of precursor and mature resident memory T cells (TRMs) that are localized in peripheral tissues.