FGF18 and cardiac hypertrophy: To confirm the effect of FGF18 on pathological cardiac hypertrophy in vivo, we used adeno-associated virus (AAV9) vectors expressing FGF18 under the control of the murine cardiac troponin-T (cTNT) core promoter, which enabled specific overexpression of FGF18 in cardiomyocytes after virus injection 2 weeks and continued overexpression for 8 weeks (AAV9-cTNT-FGF18; Supplementary Fig. 5b).