Serum and glucocorticoid-regulated kinase 1 (SGK1; EC 2.7.11.1) belongs to a family of kinases that is under acute transcriptional control by several stimuli, including serum and glucocorticoids. It is involved in the regulation of a wide variety of ion channels, membrane transporters, cellular enzymes, transcription factors, neuronal excitability, cell growth, proliferation, survival, migration and apoptosis. As such, SGK1 plays an important role in cellular stress response. SGK1 is activated by the phosphatidylinositol-3-kinase (PI3-kinase) pathway involving the 3-phosphoinositide (PIP3)-dependent kinase PDK1. Additionally, activation of SGK1 may involve the scaffold protein Na+/H+ exchanger regulating factor 2 (NHERF2), which mediates the assembly of SGK1 and PDK1. Activation of SGK1 by PDK1 may further involve the mammalian target of rapamycin mTOR and the serine/threonine kinase WNK1. SGK1 has been implicated in renal function and salt appetite, hypertension, extracellular volume regulation, obesity and metabolic syndrome, tumor growth, inflammation, and fibrosing disease.