SYT1 and cardiac hypertrophy: The above in vivo results showed that SYT1 KO enhanced the phosphorylation of p38 MAPK which contributed to TAC-induced cardiac hypertrophy, we next observed whether inhibition of p38 MAPK could rescue cardiomyocyte hypertrophy using SB203580, a specific inhibitor of p38 MAPK in the hypertrophic H9C2 cell model induced by Ang II.