PDCD1 and Stroke: Bodhankar et al. identified that PD-1 and CTLA-4 had inhibitory effects on the activation of T cells in a rodent stroke model [151] and that blockade of the PD-L1 checkpoint significantly limited the CNS inflammatory response and improved neurological outcomes by partially reversing splenic atrophy and increasing the accumulation of CD8+ Treg cells in the lesioned brain hemisphere [131].