Moreover, vitamin D3 decreased the protein expression of TNF‐α, the p‐NF‐κB p65/NF‐κB p65 ratio and p‐IκBα/IκBα ratio in the hippocampus of mice, suggesting that the protective effect of vitamin D3 on cognitive impairment caused by diabetes might be related to the inhibition of inflammatory response. The gene discussed is NFKBIA; the disease is diabetes mellitus.