Early growth response 1 (EGR1): a gene with as many names as biological functions.

Although most researchers in biology tend to focus on very specific issues and questions about their preferred gene or pathway, sometimes we face situations in which nature presents us with a remarkable example of a gene with multiple functions. Since the discovery of the early growth response 1 (EGR1) gene in the mid eighties, several independent groups attributed its activation as an immediate early response gene to extracellular stimuli such as environmental cues, growth factors, irradiation and small molecules. Even twenty-plus years after its initial cloning and characterization, EGR1 continues to attract considerable attention among biological circles. Recently, work by Wagers and colleagues reported yet another novel and rather promising function for EGR1. They demonstrated that EGR1 is involved in regulating homeostasis of hematopoietic stem cells (HSC) by coordinating proliferation and migration. Importantly, this finding allows a conduit by which manipulation of this pathway will elucidate further understanding of the biology driving HSC mobilization and transplantation in a clinical setting.