In contrast, comparison of the sex incidence (positive vs. negative: OR: 1.70, 95% CI: 0.34–1.13; p = 0.12), subacute occurrence rate (positive vs. negative: OR: 2.17, 95% CI: 0.98–4.84; p = 0.06), cerebellar ataxia occurrence rate (positive vs. negative: OR: 6.04, 95% CI: 0.30–121.73; p = 0.24), and brain lesions (positive vs. negative: OR: 3.05, 95% CI: 0.42–21.86; p = 0.27) between NF155‐positive and ‐negative CIDP patients showed no significant differences. The gene discussed is PMP22; the disease is cerebellar ataxia.