In 2017, the protective and rare coding variant rs72824905 in PLCG2 (P522R variant) was first reported to be significantly associated with the risk of AD, and this association has been confirmed in GWAS studies in several different populations in subsequent years (Sims et al., 2017; Conway et al., 2018; Dalmasso et al., 2019; Chen et al., 2021; de Rojas et al., 2021). Here, PLCG2 is linked to Alzheimer disease.