FZD9 and hydrops fetalis: These DEGs involved in the key BPs were piped to STRING to generate protein–protein interaction (PPI) networks and visualized in the BPs (Figure 3B), in which hub genes from one of the MCODE model in the PPI network including PTPRD, ITGA2, DAB2, TNC, SFRP1, CRIM1, DNER, FZD1, FZD9, KIAA1324L, DZIP1L, and TGFB2 major belonged to HF growth and development (Figure 3B).