In acute samples from 26 patients attending the emergency department with suspected sepsis (clinically suspected or proven infection, a National Early Warning Score or National Early Warning Score 2 score ≥ 5), the levels of serum biomarkers of brain injury (neurofilament light [NfL], glial fibrillary acidic protein (GFAP), total tau and ubiquitin C-terminal hydrolase L1) and p-tau-217 were compared to age- and sex-matched non-infected controls, with further assessment of the correlation between the biomarker levels and cytokine profiles. The gene discussed is GFAP; the disease is Sepsis.