NRG1 and hydrops fetalis: Interestingly, in the group of selected 34 ‘cardiac ageing genes’, there were genes that could be assigned to cardiac adaptation (Nrg1, Cilp, Nppb) [62, 105, 106] or maladaptive processes (Cdkn1a, Timp1, Egr2, Egr3, Gdf15, Sfrp2, Itga11) [54–61], underscoring the importance of crosstalk between mechanism activating and inhibiting HF development among those activated by accelerated cardiac ageing in HF.