Compared to Aβ- CN, CSF concentrations of osteoprotegerin (OPG) were significantly increased in both Aβ- MCI patients (d = 0.23; q = 0.004) and patients with AD (d = 0.2; q = 3.75 × 10− 8; see Fig. 1a and Table 2). The gene discussed is TNFRSF11B; the disease is Alzheimer disease.