Identifying independent causal cell types for human diseases and risk variants.

Cell-type fine-mapping reveals 79 independent cellular mechanisms explaining 39% of trait heritability across 63 GWASs.

• Why it matters: Understanding which specific cell types drive complex traits is crucial for targeted therapies and clarifies disease biology, yet distinguishing independent cellular contributions remains challenging.
• What they did: Using probabilistic methods CT-FM and CT-FM-SNP on GWAS data and regulatory annotations, the study identified independent cell-type sets and assigned high-confidence causal cell types to over 3,000 non-coding variants.
• The result: Findings show most variants act through a single cell type, while pleiotropic variants can influence multiple cell types, enabling detailed dissection of cellular architecture underlying complex traits.