KCNJ4 is a gene that provides instructions for making a protein known as a potassium ion channel. This channel is important for regulating the flow of potassium ions in and out of cells, which is crucial for maintaining the electrical balance and proper functioning of various tissues, especially in the heart and kidneys. Mutations in the KCNJ4 gene can lead to health issues, such as Bartter syndrome, a condition that affects kidney function and electrolyte balance. Understanding KCNJ4 is essential for researchers studying these conditions and developing potential treatments.