MAPK1 and hydrops fetalis: GSK-3α-mediated activation of the RAF-MEK-ERK MAPK pathway in mouse cardiac fibroblasts has been shown to enhance the production of fibrotic proteins, such as IL-11 and collagen-1, promote fibroblast-to-myofibroblast transformation, and exacerbate injury-induced cardiac remodeling and dysfunction, thereby accelerating HF progression [39].