Genomic studies often involve estimating and comparing many effects across multiple conditions or outcomes. Examples include studying changes in expression of many genes under multiple treatments1, differences in histone methylation at many genomic locations in multiple cell lines2, effects of many genetic variants on risk of multiple diseases3, and effects of expression quantitative trait loci (eQTLs) in multiple cell-types or tissues4–6. Analyses often aim to identify “significant” non-zero effects, and to identify differences in effects among conditions (e.g., tissue-specific effects), which may yield biological insights.
