Moreover, HSV-1-specific IgG3 were more frequently detected in MCI patients (88%) compared to HC (66%, p = 0.008) and to AD patients (77%), whereas the serum concentration of these antibodies was similar in the three groups (AD: 0.66; 0.48-0.80; MCI: 0.66; 0.47–0.86; HC: 0.66; 0.53–0.88) (Table 1). The gene discussed is IGHG3; the disease is Alzheimer disease.