In the future, the role of eIF5A, its hypusination-dependent activity, and upstream catalytic enzymes need to be thoroughly investigated in cardiomyocytes to better understand the cardioprotective effect of spermidine, a precursor metabolite for hypusination of eIF5A in humans [195], as well as the impact of hypusinated eIF5A in heart failure with reduced or preserved ejection fraction as both manifest severe cardiac fibrosis as a common hallmark [194,196]. The gene discussed is EIF5A; the disease is heart failure.