Although we provide new insight with the largest and most comprehensive study of cell type enrichment in brain-related disorders, our results should be interpreted in light of inevitable limitations. First, using MAGMA it is possible to test whether the genes specific to a phenotype are enriched in genetic associations of that phenotype while controlling for genetic associations of another phenotype [10]. However, as our main goal was to identify enriched cell types, such conditional analyses are beyond the scope of this study. Second, we found that microglia associated with age-induced neuroinflammation were exclusively found to be enriched in Alzheimer’s disease using human scRNA datasets, whereas no enriched glial cells were identified using mouse scRNA datasets. Therefore, mouse gene expression data from not only a spatial, but also a temporal resolution is warranted for future research to identify cell types implicated in disease during development. Additionally, improved coverage of brain-related regions, such as the entire CNS [10], is warranted for future research. Third, a potential limitation of the FUMA model is that averaging gene expression disregards that low expression levels of
