**4. Conclusion**

In conclusion, calcium signaling alterations occur in multiple cellular components, human breast stem cells, human breast epithelial cells, human breast myoepithelial cells, human breast adipocytes, human breast telocytes, etc., including those which contribute to the development and progression of breast cancer. Moreover, several molecular actors (e.g., voltage-gated calcium channels, TRP channels, STIM/Orai proteins, hEag1 K<sup>+</sup> channels, calcium-activated potassium channels, calcium-activated chloride channels, muscarinic acetylcholine receptors, etc.) are playing an important role in calcium-altered homeostasis associated with breast cancer that might be considered as potential pharmacological targets. Considering the interplay between the above-described calcium signaling pathways, the most efficient strategy against breast cancer would simultaneously target several molecular players.
