Cardiac fibroblasts (CFs) are numerically a highly abundant cell type in the heart and are responsible for the homeostasis of the extracellular matrix (ECM) in the myocardium under normal conditions. Upon cardiac stress, these cells become activated and transdifferentiate into myofibroblasts (MyCFs), which are characterized by their increased capacity to proliferate, migrate, and secrete ECM components and bioactive molecules. The trans-differentiation of CFs is induced by several factors like angiotensin II (Ang II) and transforming growth factor-ß (TGF-ß and is crucial in cardiac remodeling. In recent years, signal mechanisms playing a role in MyCFs behavior have been intensively investigated, including the role of the universal second messenger calcium (Ca 2+).