MMP9 and Alzheimer disease: In APOE ε4 + AD individuals, CHI3L1 correlated with IL1B (r = 0.582; q = 0.009; CI 0.21 to 0.81), LRP1 (r = 0.799; q < 0.0001; CI 0.57 to 0.91), and MMP9 (r = 0.585; q = 0.009; 0.19 to 0.82) (Figures 3F–J).