RNF2 and hydrops fetalis: The combined domains between Bmi‐1‐RING1B and GATA4 in aging cardiomyocytes could be therapeutic targets for identifying small molecular peptides in clinical applications to promote the combination of Bmi‐1‐RING1B with GATA4 and the ubiquitination of GATA4 to prevent SA‐PCH and HF.