ERBB2 and triple-negative breast carcinoma: As Orai2 has been reported to modulate Ca2+ influx through CRAC channels primarily formed by Orai1 subunits, we first explored the expression of Orai1 and Orai2 at the transcript and protein level in non-tumor breast epithelial cells as well as in ER+, HER2 and triple negative breast cancer cells (TNBC).