In in vitro models of cardiac hypertrophy obtained by stimulating rat cardiomyocytes with phenylephrine or endothelin-1—two GPCR agonists -, Selumetinib, PD98059, PD184352, and U0126 inhibited ERK activation and attenuated markers of cardiac hypertrophy, like protein synthesis and cell size enlargement (172, 177, 178). Here, MAPK1 is linked to cardiac hypertrophy.