Résumé : Glucocorticoid hormones are effective in inhibiting inflammatory responses, but the mechanisms that confer this action have not been completely elucidated. The prevailing view is that these compounds inhibit novel gene transcription regulated by the nuclear factor kappa B and/or activator protein-1 transcription factors. In the last few years, several reports have shown that glucocorticoids can also block signal transduction in lymphocytes at an early, postreceptor step, suggesting novel molecular targets for these hormones. These data will be briefly reviewed and the possible in vivo relevance of these findings discussed, with particular emphasis on T cell development.