MAPK8 and cardiac hypertrophy: In myocardial I/R mice, Dillmann and colleagues showed that knockout of Hsp70 genes resulted in the development of cardiac hypertrophy after myocardial I/R injury, which may be related to several signaling pathways including Jun N-terminal kinase (JNK), p38 MAPK, Raf-1, and extracellular signal-regulated kinase (ERK) [42].