KLF3 and hydrops fetalis: In summary, we found that overexpression or inhibition of miR-21 could affect the gene expression of CNKSR2, KLF3 and TNPO1. Furthermore, the miR-21-CNKSR2-MAPK, miR-21-KLF3, miR-21-TNPO1-CCR2 pathway was found in HF cell development.