The small GTPase Rap1 is an immediate downstream target for Hoxb4 transcriptional regulation

The Hox genes are a family of homeodomain-containing transcription factors which determine anteroposterior identity early on in development. Although a lot is now known about their regulation and function, very little is known of their effector (downstream target) genes. Here we show that the small GTPase Rap1 is a direct, negatively regulated target of Hoxb4 and is excluded from Hoxb4 expressing cells.