Given that individual annexins and S100A proteins have been implicated in cancer initiation and progression, and modulation of calcium signaling has been demonstrated to change sensitivity of chemotherapeutic agents to apoptotic signals [32], we further investigated how the combined overexpression of annexins/S100A proteins, as identified in this study, may contribute to treatment resistance and breast cancer recurrence and metastasis. This evidence concerns the gene S100A1 and breast carcinoma.