CD274 and stroke disorder: Likewise, the PD-L1 blockade has also re-invigorated IFN-γ-compromised CD8+ T cell responses against the varicella virus [125], which causes latent herpes infection, as approximately 90% of world population possess the latent zoster infection; reactivation of the virus occurs in almost 50% of them and could promote vasculopathy to increase the risk of stroke and cardiovascular events, even among patients above 40 years of age [126].