The G0/G1 switch protein 2 (G0S2) is a regulatory protein that plays a role in the transition between the G0 and G1 phases of the cell cycle, crucially involved in regulating cell proliferation, differentiation, and lipid metabolism. G0S2 participates in the metabolic regulation of fatty acids by inhibiting lipase activity, particularly through interaction with fatty acid-binding protein 4 (FABP4). It is expressed in various tissues, especially abundant in the liver, adipose tissue, and immune cells, with its expression regulated by nutritional status and inflammatory signals. Mutations in the G0S2 gene or changes in its expression are associated with a variety of diseases, including obesity, diabetes, and certain cancers. By affecting lipid metabolism and cell cycle regulation, G0S2 plays an important role in maintaining the homeostasis of cells and tissues.