KCNK1 (also named TWIK-1 or K_2P1.1) is a member of the 2-pore (2P) domain K⁺ channels family that, currently, includes 16 members. These channels show little time- or voltage-dependence and are considered to be “leak” or “background” K⁺ channels, thereby generating background currents which help set the membrane resting potential and cell excitation. The K_2P channels have a signature topology that includes four transmembrane domains and two pore domains with intracellular N- and C termini. 

K_2P channels are regulated by diverse physical and chemical stimuli including temperature, pH, mechanical stretch, inhalation anesthetics, etc. but are insensitive to the classical K⁺ channel blockers.

KCNK1 was the first of the K_2P channels to be identified and as its original name indicates (Tandem of P domains in a Weak Inward rectifier K⁺ channel) the channel behaves as a weak inward rectifier when expressed in heterologous systems. The channel is ubiquitously expressed with the most prominent expression in the brain, kidney and heart.