SFRP4 and hydrops fetalis: Therefore, these genes (SMOC2, NRK, PDE5A, CTSK, MXRA5, CRISPLD1, COL14A1, SFRP4, OGN, PI16, HTRA1 and C1QTNF2) might be the biomarkers of HF, which could regulate organization of ECM to affect HF progression.