ORAI1 and breast cancer: For instance, Orai1 appears to be upregulated in the poor prognosis basal breast cancer molecular subtype [53], and silencing of ORAI1 reduces the proliferation of breast cancer cell lines in vitro [53, 54] and in vivo [54], the invasiveness of MDA-MB-231 breast cancer cells in vitro, and metastasis in vivo [20].