ARTC2, also known as ART2. 2, is a 35 kD, GPI-anchored, and cell surface ADPribosyltransferase that is highly expressed by regulatory T cells (Tregs) and natural killer T (NKT) cells. ARTC2 is enzymatically active at 4°C. Through the ribosylation of the ion channel P2X7, ARTC2 mediates NAD+-induced cell death (NICD) and the proteolytic shedding of CD27 and CD62L. Blocking the activity ARTC2 with Treg-Protector improves the recovery of Tregs and NKT cells during their isolation from lymphatic and peripheral tissues.