ESR1 and breast cancer: Further evidence of association between ERα status and breast cancer, is the report of increased levels of ORAI3 in ERα-positive breast cancer cell lines compared to ERα-negative breast cancer cell lines, the contribution of ORAI3 to SOCE in ERα-positive breast cancer cell lines but not those which lack the ERα [30] and the ability of ERα silencing to significantly reduce ORAI3 expression in MCF-7 cells [29].