The LIF cytokine: towards adulthood

The aim of this article is to recapitulate the key features of leukaemia inhibitory factor cytokine (LIF), to review its numerous physiological effects and to comment on the most recent data. We will also pres- ent results of transcriptome analyses, which have highlighted different categories of LIF targets, identified in murine embryonic stem (ES) cells and early derivatives. We hope to stimulate new research fields on this puz- zling cytokine, which, forty years after its discovery, has still not disclosed all its secrets.