K2P4.1 (also named TWIK-related arachidonic acid stimulated K+ channel, TRAAK or KCNK4) is a member of the 2-pore (2P) domain K+ channels family that at the moment includes 15 members. These channels show little time or voltage dependence and are considered to be “leaky” or “background” K+ channels, thereby generating background currents which help set the membrane resting potential and cell excitation. The K2P channels have a signature topology that includes four transmembrane domains and two pore domains with intracellular N- and C- termini.