The K<sub>ir</sub>2.6 also known as inward rectifier potassium channel 18 is a protein that in humans is encoded by the KCNJ18 gene. K<sub>ir</sub>2.6 is an inward-rectifier potassium ion channel.
Inwardly rectifying potassium channels, such as K<sub>ir</sub>2.6, maintain resting membrane potential in excitable cells and aid in repolarization of cells following depolarization. K<sub>ir</sub>2.6 is primarily expressed in skeletal muscle and is transcriptionally regulated by thyroid hormone.
Mutations in this gene have been linked to thyrotoxic periodic paralysis.