KCNF1 is a multi-pass membrane-bound protein that acts as an ion channel and is generally expressed as a heterotetramer of potassium channeling proteins. Formerly known as kH1, KCNF1 is usually found as a heteromer with three other potassium channel proteins, KCNG3, KV6.3 and KCNV2. As a potassium channel protein, KCNF1 plays a role in regulating apoptosis and proliferation of pulmonary artery smooth muscle (PASM) cells. Bone morphogenetic proteins (BMPs) restrict proliferation and can induce apoptosis in normal human PASM cells and will upregulate expression of KCNF1 in PASM cells in vitro. KCNF1 is expressed in heart, brain, liver, skeletal muscle, kidney and pancreas.