We found that in obesity-induced cardiac hypertrophy mice, obesity led to increased CARD9 expression, p38 MAPK activation, and the increased expression of the hypertrophy-related genes of GATA4 and MEF2c. Inhibition of p38 MAPK activity then decreased GATA4 and MEF2 expression, but CARD9 expression was unchanged. This evidence concerns the gene CARD9 and cardiac hypertrophy.