RAG1 and Stroke: Interestingly, this set of chemotactic genes induced by TREG cells were also differentially expressed in microglia isolated from Rag1−/− mice in comparison to WT mice (Figure 2E, F), suggesting that the stroke associated microglia may lose their chemotactic properties in a T cell-dependent manner and especially a TREG cell dependent (Chen and Bromberg, 2006).