SMAD3 and hydrops fetalis: Based on the KEGG pathway analysis of the DEGs and DMGs, we found that PDGFC and SMAD3 were involved in the signaling pathways identified, which include roles in gap junction, EGFR tyrosine kinase inhibitor resistance, TGF-beta signaling and adherens junction, that are essential for proliferation, differentiation, and communication of HF cells during movement (Young et al., 2003; Arita et al., 2004; Plasari et al., 2010; Oshimori and Fuchs, 2012; Gay et al., 2015; Flores et al., 2018).