It is within the T cell rich zone of secondary lymphoid organs (SLO) that dendritic cells (DC) present the captured pathogens to recirculating T cells in order to activate the rare antigen-specific T cells. While we have made considerable progress in understanding the biology of mobile hematopoietic cells found within SLO, notably DC and lymphocytes, we still have a lot to learn about the sessile stromal cells. This review is focused on the recent progress made in our understanding of the fibroblastic reticular stromal cells that form the 'niches' within the T zone.