Although there was no significant correlation between olfactory function and serum TNF-α level in patients with BD and SP in remission, there was a correlation between cognitive function and olfactory function or serum TNF-α, suggesting that improving olfactory function or alleviating the systemic inflammatory response may be beneficial to the recovery of cognitive function, so as to promote the rehabilitation of patients with SP and BD. The gene discussed is TNF; the disease is Behcet disease.