CHEK1 and Alzheimer disease: Methylation at the cg18714484 in CHEK1 was decreased in AD cases compared to controls in ε4 carriers (P = 2.2 × 10−6; Supplementary Table 3) and inversely associated with global cognitive (P = 1.8 × 10−5), memory performance (4.2 × 10−5) and ventricle volume (P = 8.1 × 10−4).