A retrospective on the requirements for γδ T-cell development

Since the discovery of gamma delta T cells two decades ago, considerable effort has been made to understand their developmental program, their antigen specificity, and their contribution to the immune response. In this review, we focus on what is known about gamma delta T-cell development and on the advances that have been made in determining which genes are required. In addition, we compare the genetic requirements for alpha beta and gamma delta T-cell development with the hope of gaining a better picture of the signaling pathways that govern the development of gamma delta lineage cells.