Serine/threonine-protein kinases SGK represent a kinase subfamily with orthologs found across animal clades and in yeast (compare Treefam family TF320906). In most vertebrates, including humans, there are three isoforms encoded by the genes SGK1, SGK2, and SGK3. The name Serum/glucocorticoid-regulated kinase refers to the first cloning of a SGK family member from a cDNA library screen for genes upregulated by the glucocorticoid dexamethasone in a rat mammary epithelial tumor cell line. The first human family member (human SGK1) was cloned in a screen of hepatocellular genes regulated in response to cellular hydration or swelling.
The term SGK is also used as a synonym for SGK1.