CLN5 and hydrops fetalis: It is well known that dWAT can secrete some critical regulator molecules that participate in the regulation of HF homeostasis, including BMPs (Plikus et al., 2008), PDGF (Festa et al., 2011), DKK1 and Sfrp4 (Chen et al., 2014), and HGF (Nicu et al., 2021).