NPPB and hydrops fetalis: They also displayed smaller overall heart size (Fig. 7h), lower HW/BSA ratio (Fig. 7i), smaller single myocyte size (Fig. 7j), lower expression of hypertrophy biomarkers ANP, BNP and β-MHC (Supplementary Fig. 6e), and less collagen deposition (Supplementary Fig. 6f) after 8 weeks of LADL, indicating that cardiomyocytes-specific knockout of lnc9456 could protect cardiac function and prevent the development of the LADL-induced maladaptive remodeling and HF.