MAPK1 and cardiac hypertrophy: p38α/β dominant negative overexpressed mice display a cardiac hypertrophic response, which is also displayed by wild type mice.[118] Similarly, overexpression of dominant negative MKK3 and MKK6, upstream activators of p38 pathways also develop cardiac hypertrophy.[112] Similarly, overexpression of p38 in mice does not result in cardiac hypertrophy, which coincides with knockout studies.[139]