In this study, the investigators observed that in the comparison of lymphocyte subsets between PNS patients before treatment and the controls, CD8+ cytotoxic T cells in patients increased and CD4+ helper T cells decreased, CD4+/CD8+ significantly decreased or even inverted, and the results were the same with reports at home and abroad in recent years [14]. The gene discussed is CD8A; the disease is paraneoplastic neurologic syndrome.