The identification of a specific subset of brain cell types being implicated in various brain disorders only marks the beginning of elucidating causal biological pathways. One question future research should address is what the effects of genetic variants in the non-coding genome are. One way to address this question is using an activity-by-contact model [37]. This model allows for the identification of cell type-specific enhancers and their target genes by leveraging single-cell chromatin accessibility and enhancer activity data. Additional insight could be obtained by performing cell prioritization analyses from human post-mortem brain samples and/or induced pluripotent stem cells from individuals with relevant genetic backgrounds using LDSC, MAGMA, and DEPICT to identify genes that are predicted to be functionally similar to causal genes. Importantly, enriched cell types are not necessarily causal, but might be part of a neural network. To confirm our findings and to elucidate causality, selective chemo- and optogenetic manipulation of identified enriched cell types in rodents might provide additional insight in the role these cells play in the neural circuit underlying brain disorders [38]. Additionally, the recently developed
