For the most stringent threshold for SNPs (p-value<0.001) ALIGATOR identified 102 and 122 categories of genes in OZALC-NAG and SAGE respectively (category-specific p-value<0.05)(Table 2). Seven GO terms were significant for both studies (Table S2) but no significant KEGG pathways were common to both studies. Moreover, all seven GO terms were also significant for the ARIC study (p-value<0.05) (Table S2). These terms group genes in the cluster of cholinergic nicotinic receptor genes on chromosomes 15 and 8, and closely related genes.