Indeed, while alterations in the Cdc42 and Rac1 signaling of cardiomyocytes affect the development of cardiac hypertrophy and heart failure, these Rho GTPases can have important roles in other cell types of crucial importance in the heart, including cardiofibroblasts [36,37] and endothelial cells [38,39]. Here, CDC42 is linked to cardiac hypertrophy.