Dexamethasone is potent glucocorticoid anti-inflammatory agent which regulates T-cell survival, growth and differentiation. It is known by various trivial and systematic names including 9-alpha fluoro 16-alpha methylprednisolone. Dexamethasone is also used as an inducer of gene expression using a dexamethasone-inducible promoter system. In horse racing Dexamethasone is one of many steroids drugs which are prohibited but is commonly used in racing stables as a treatment for respiratory complaints.