KCNJ8 and metabolic disease: The Kir6.2 subunit has more intrinsic sensitivity to cellular metabolic disorders than the Kir6.1 subunit.16 In addition, the composition of the mitochondrial KATP (mitoKATP) channels is still unclear, although some literature suggests that Kir6.1 may be a functionally important part of mitoKATP channels in native heart cells.17