The funny current is highly expressed in spontaneously active cardiac regions, such as the sinoatrial node (SAN, the natural pacemaker region), the atrioventricular node (AVN) and the Purkinje fibres of conduction tissue.
In the heart, a strong electrical signal is present in areas that naturally regulate its rhythm, including the sinoatrial node (SAN), the atrioventricular node (AVN), and the Purkinje fibers. This signal is responsible for the heartbeat's natural pace.