design: CD4+Foxp3(GFP)+ Treg cells were FACS-isolated from the pericontusional brains tissue and from blood of the sham and injured mice at 7 days post-TBI. For brain samples, each RNA sequencing sample is a pool of 5 ipsilateral hemispheres and 20 sham brain hemispheres. For blood samples, each RNA sequencing sample is a pool of 5 mice. Preparation for RNA libraries for sequencing was performed using standard Illumina protocols.