ARHGAP20 and Alzheimer disease: The association between rs6538127 and NAV3 expression in astrocytes (Fig. 2e; LRT—P = 1.23 × 10−6, q = 4.93 × 10−5) was influenced by both multiple sclerosis (MSinteractionP = 2.02 × 10−5) and AD samples (ADinteractionP = 2.94 × 10−3), while rs7932358 and ARHGAP20 expression in oligodendrocytes (Fig. 2f; LRT—P = 4.75 × 10−8, q = 2.10 × 10−6) was influenced by all three disease states (Parkinson’s disease (PD)interaction, P = 3.57 × 10−4; MSinteraction, P = 1.39 × 10−3; ADinteraction, P = 8.96 × 10−6).