To date, >60 genes causative for AF have been discovered, of which the vast majority code for ion channel subunits of potassium (such as KCNQ1), natrum (such as SCN5A) and calcium (such as CACNA1A), gap junction proteins/connexins (such as GJA1/Cx43), cardiac transcription factors (such as TBX5), signaling molecules (such as ANP), and myocardial structural proteins (such as TTN) [2,49,50,51,61,62,63,64,65,66,67,68,69,70,71,72]. The gene discussed is TBX5; the disease is atrial fibrillation.