Interestingly, CD8+ T cells exhibited a nonuniform distribution of functional states with significant enrichment for terminal effector CD8+ T cells (C6 cluster, t-test, FDR = 0.015) and depletion of naïve CD8+ T cells (C5 cluster, t-test, FDR = 0.012) in the blood of PD patients (Fig. 3a). The gene discussed is CD8A; the disease is Parkinson disease.