The number of NeuN-positive cells was also significantly higher in the hippocampal CA1 region of 12-month-old APPKI-SRRKO mice compared with age-matched APPKI mice (p < 0.05, Figure 4E), suggesting that suppressed D-serine synthesis in the AD brain can reduce hippocampal neuronal damage. The gene discussed is RBFOX3; the disease is Alzheimer disease.