MMP9 and early-onset autosomal dominant Alzheimer disease: Genome-wide association study meta-analysis conducted mainly on participants of European origin showed a little evidence that MMP-9 expression quantitative trait loci (eQTLs) and protein quantitative trait loci (pQTLs) affected the odds of Alzheimer’s disease (p = 0.45 and p = 0.51) (Anderson et al., 2022).