Orai2 is a 254 amino acid multi-pass membrane protein that belongs to the orai family of proteins. Localizing to the plasma membrane, Orai2 plays an important role in store-operated calcium (SOC) entry, a process involving Ca2+ influx and replenishment of Ca2+ stores formerly emptied through the action of inositol 1,4,5-trisphosphate production and other Ca2+ mobilizing agents. CRAC channels are responsible for medi-ating calcium influx in T-cells and play an important role in the immune response. Orai2 specifically increases the Ca2+-selective current through coaction with the Ca2+ sensor Stim1.