Further mapping indicates that the number of naïve CD8+ T cells is reduced (He et al., 2022) and that a large population of CD8+ T cells continuously progress from central memory to terminal effector T cells in the blood and CFS of PD patients based on single-cell transcriptome expression combined with TCR-sequencing (Wang P. et al., 2021). This evidence concerns the gene CD8A and Parkinson disease.