A, TOR activity dynamics in fish hearts injected with DOX (20 μg/gbm) with or without rapamycin (0.2 μmol/L) treatment. B, TOR activity in fish hearts dissected from tr265 sibling and tr265 homozygous mutant with or without rapamycin (0.4 μmol/L) treatment. C, Representative images of dissected fish hearts at week 4 post-DOX (20 μg/gbm) injection with or without rapamycin (0.2 μmol/L) treatment. Scale bar=1 mm. D, Quantification of ventricle area to body weight index (VA/BW) at different time points post-DOX injection with or without rapamycin (0.2 μmol/L) treatment. E, Quantification of VA/BW index at different ages of tr265 fish compared to sibling with or without rapamycin (0.4 μmol/L) treatment. F, Quantification of VA/BW index to show one-week rapamycin (0.4 μmol/L) treatment attenuates phenylhydrazine (PHZ) induced heart enlargement at both 5 weeks and 12 weeks old fish. *P<0.05. ns, not significant. V, ventricle; A, atrium; OFT, outflow tract.