APOE and Alzheimer disease: While median CHI3L1 ΔCt values (indicating higher expression) within the AD group were lower in APOE ε4 carriers (n = 23; median = 0.60, IQR: −1.20 to 3.4) compared to non-ε4 carriers (n = 12; median = 3.25, IQR: 1.30 to 4.10), significance was lost after Holm-Šidák correction (p = 0.061; Hodges-Lehmann median difference = −1.7; 95% CI = −3.6 to 0; Figure 2A).