MAPK8 and heart failure: MAPK signaling pathways, such as extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal protein kinase (JNK) and p38 MAP kinase, are demonstrated to be actively involved in myocardial dysfunction [9,10], hypertrophy [11,12,13], fibrosis [14,15,16] and heart failure [17,18,19].