PITX2 and atrial fibrillation: Constitutive adult Pitx2c heterozygous and conditional Pitx2 ko mice display shorter action potential duration and lower resting membrane potential [89,90], as a result of modulation of multiple targets, including transcription factors, ion channels, calcium handling genes, microRNAs as well as other AF susceptibility genes [88,89,90,122,123,124].