ACTA1 and hydrops fetalis: Mechanical forces in the ECM activate the RhoA/ROCK mechanical signaling pathway through mechanical sensors such as integrin, and then ROCK induces the phosphorylation of myosin light chain (MLC), increases the expression of transforming growth factor-β (TGF-β) and α-SMA proteins, and activates HSCs to promote HF(Parsons et al., 2010).