The ANTs exchange ATP/ADP across the mitochondrial inner membrane and regulate the mtPTP.

There are several ANT isoforms, ANT1 and ANT2 being expressed in both fetal and adult heart.

Inactivation of the mouse Ant1 gene permits normal cardiac development but results in adult hypertrophic cardiomyopathy.

Inactivation of the mouse Ant2 gene is embryonic lethal associated with cardiac hypertrabeculation/noncompaction.

The differential cardiac toxicity of Ant1 & Ant2 inactivation is hypothesized as differential regulation of the mtPTP.