GPC2 and Alzheimer disease: Of the 123 known genes reaching genome-wide significance, 8 were included in the top 5% of hits: OR2AE1, GPC2, PVRIG, PILRA, AGFG2, TRIM35, EPHX2 and FERMT2 (Fig. 2a) suggesting that these genes could be involved in the AD process via the regulation of APP metabolism.