minor allele frequencies did not differ significantly across the 26 Arms. We evaluated rs2072661 and rs1051730 genotype distributions by randomization arm and observed two arm-by-SNP strata with Hardy-Weinberg equilibrium p-values<0.05, versus 2.5 expected by chance (See Table, Supplemental Digital Content 5: nAChR SNPs counts and Hardy-Weinberg equilibrium P value, by arm).
