RAC1 and cardiac hypertrophy: Notably, induction of Rac1 S-palmitoylation in DTgZdhhc3 hearts occurred within 2 weeks of transgene expression, prior to the development of cardiac hypertrophy and heart failure (Fig. S4), suggesting that modification of Rac1 may be a proximal mechanism underlying zDHHC3 activity–induced cardiac pathology.