WNK1 (WNK Lysine Deficient Protein Kinase 1) is a serine/threonine kinase that plays a crucial role in regulating electrolyte balance and blood pressure. It affects sodium and potassium transport in the kidneys, aiding in the maintenance of fluid balance and vascular function. Variants of WNK1 can disrupt this regulation, contributing to hereditary hypertension and electrolyte disorders.