While TSPO is known to be an early biomarker in the neuroinflammation cascade, another longitudinal investigation, using 18F-FSPG and 18F-DPA-714, in the cerebral ischemia model displayed an earlier expression of the cystine/glutamate antiporter (system xc-), involved in glutamatergic excitotoxicity, compared to TSPO imaging, evidencing its novel role on inflammation after cerebral ischemia [221]. The gene discussed is TSPO; the disease is brain ischemia.