PITX2 and atrial fibrillation: To date, multiple genetic variants have been associated with AF, including variants in the 4q25 locus containing the paired-like homeodomain 2 (PITX2) gene associated with the development of pulmonary vasculature [1], the 1q21 locus containing the member 3 potassium intermediate/small conductance calcium-activated channel member 3 (KCCN3) gene involved in cardiac conductance [2], and the 16q22 locus containing the zinc finger homeobox 3 (ZFHX3) gene with unknown functional significance [3].