TP53 and hydrops fetalis: In transverse aortic constriction (TAC)-induced WT and myocardial p53 deficient (p53<sup>CKO</sup>) mice HF model, as well as Ang II-induced human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), we evaluate cardiac protection of modhTERT via echocardiography, RNA-sequence, Western blotting, Proteome Profiler Mouse XL Cytokine Array panel, RT-qPCR, transmission electron microscopy, and immunofluorescence.<h4>Findings</h4>AAV9-modhTERT<sup>Y707F, D868A</sup> reversed cardiac function decline and prevented onset of cardiac fibrosis in TAC-induced HF murine.