ORAI1 and breast cancer: Recent studies have reported that hypoxia, but not the epidermal growth factor (EGF), another EMT (epithelial–mesenchymal transition) inducer, is able to increase Orai3 expression in the triple-negative breast cancer cells MDA-MB-468, HCC1569 and MDA-MB-231 as well as in the EMT breast cancer cell line PMC42LA, while the other Orai proteins, Orai1 and Orai2, were not up-regulated.