S100A1 and hydrops fetalis: Perfusion, specifically in HF conditions, was able to increase the expression of key genes in cardiac morphologic and functional maturation, namely: (i) intercellular communications (Connexin 43); (ii) automaticity (HCN channels); (iii) myocyte repolarization (K + channels), (iv) sarcomeric structure (myosin heavy chains, sarcomeric actin, troponins, and regulatory myosin binding protein C), (v) calcium cycling and sensitivity (SERCA2, Calsequestrin‐2, Junctophilin‐2, S100A, RYR2), and (vi) metabolism and mitochondrial biogenesis (PGC‐1A).