STIM1 and breast cancer: By contrast, attenuation of SARAF expression significantly reduced SOCE in breast cancer MCF7 cells, where SOCE is strongly dependent on STIM1, STIM2, and Orai3 [9] (Figure 2d,e,g,h; p < 0.05–0.001 Student’s t test; n = 40 cells/day/3–5 days).