C4B and Alzheimer disease: It should also be stressed that even though AD patients in our cohort are ∼10 yr older than controls, we do not see the accumulation of MD-CH with age in this group, which is in contrast to reports showing higher frequency of CHIP in older individuals (Niroula et al, 2021; Kamphuis et al, 2023), and supporting the hypothesis of CHIP being the factor reducing the AD risk.