COL1A2 and hydrops fetalis: Using both sequencing and weighted gene co-expression network analysis, which included COL1A1, COL1A2, KRTAP3-1, FA2H, etc., 12 genes were obtained and were significantly related to HF development; in addition, the ECM-receptor interaction, focal adhesion, PI3K/Akt and MAPK signaling pathways were the main pathway related to HF growth and development [33].