PITX2 and atrial fibrillation: However, genome-wide association studies suggested genetic variation contributes to AF susceptibility, with >100 AF-associated loci reported to date (Nielsen et al., 2018), including the atrial-selective transcription factor PITX2 (paired like homeodomain-2) that regulates membrane effector genes associated with AF (Gudbjartsson et al., 2007; Chinchilla et al., 2011; Kirchhof et al., 2011; Qiu et al., 2014; Tao et al., 2014; Lozano-Velasco et al., 2015; Pérez-Hernández et al., 2015; Bai et al., 2018; Mechakra et al., 2019).