Tpit determines alternate fates during pituitary cell differentiation.

The T-box transcription factor Tpit was identified as a cell-specific factor for expression of the pituitary proopiomelanocortin (POMC) gene. Expression of this factor is exclusively restricted to the pituitary POMC-expressing lineages, the corticotrophs and melanotrophs. We have now determined the role of this factor in pituitary cell differentiation.