Association signal plot for SNPs mapping to CYP2B6. Each point represents a SNP in the association analysis, plotted with their p-value (on a -log10 scale) as a function of genomic position (NCBI Build 36). The lead SNP (with maximal association signal) is represented by the purple symbol. The shape of the plotting symbol corresponds to the annotation of the SNP: square for synonymous or UTR; and circle for intronic or non-coding. The colour coding of all other SNPs indicates LD with the lead SNP (estimated by CEU r2 from Phase II HapMap): red r2 ≥ 0.8; gold 0.6 ≤ r2 < 0.8; green 0.4 ≤ r2 < 0.6; cyan 0.2 ≤ r2 < 0.4; blue r2 < 0.2; grey r2 unknown. Recombination rates are estimated from Phase II HapMap and gene annotations are taken from the University of California Santa Cruz genome browser.