STIM1 and cancer: Invadopodia were detected in 90~100% of breast cancer MDA-MB-231 cells (Fig. 2b and c) and 80~90% of osteosarcoma U2OS cells (Fig. 2e and f), whereas suppressed STIM1 expression by two STIM1-specific siRNAs (Fig. 2a and b) significantly decreased the number of invadopodia per cell in these two cancer cell lines (Fig. 2c and f).