(a) based on current methodologies that rely on absolute gene expression levels, Gene 1 is not defined as cell type-specific while Gene 2 is defined as cell type A specific showing higher gene expression in cell type A than in cell type B. (b) based on methods that look at variation in gene regulation mechanisms, such as expression quantitative trait loci or eQTLs, across cell types, Gene 1 is defined as cell type A specific while Gene 2 is defined as cell type B specific. These genetic effects on gene regulation can be more informative in deciphering the functional role of disease-associated variants at cell type resolution.