MAPK8 and atrial fibrillation: The hepatic protein expressions of p-ASK1/ASK1 (Figure 4A), p-JNK/JNK, p-p38/p38, and p-ERK1/2/ERK1/2 (Figure 4B) among four groups were determined by western-blot, and found that their expressions were significantly reduced in AF/CSO group compared with that in AF/CO group.