PKP2 and hydrops fetalis: Current research indicated that PKP2 deficiency in cardiomyocytes could enhance transforming growth factor β1 (TGF‐β1) and p38 mitogen‐activated protein kinase (MAPK) signaling, promoting pro‐fibrotic gene expression [18], but their mechanistical role in fibrosis in the setting of HF has not been systemically explored.