MC1R and persistent truncus arteriosus: Consistent with the TAC model, hematoxylin and eosin–stained cardiac cross‐sections and measurement of tissue weights at euthanasia showed blunted hypertrophic growth of the heart in angiotensin II–infused Mc1r‐cKO mice compared with Myh6‐MCM control mice (Figure 5A through 5C).