MAPK8 and Myocardial fibrosis: Abnormal activation of two key branches—extracellular signal-regulated kinases 1/2 (ERK1/2) and c-Jun N-terminal kinases 1/2 (JNK1/2)—fosters CFs proliferation and collagen maturation, thereby worsening myocardial fibrosis (Yousefi et al., 2020).