Genomic DNA was extracted from whole blood using the Qiagen Flexigene DNA Kit (Qiagen). The rs12979860 SNP was genotyped by allelic discrimination using a TaqMan Custom SNP Genotyping Assay (Applied Biosystems) on an ABI 7500 Real-Time PCR System (Applied Biosystems). rs368234815 was genotyped by Sanger sequencing using BigDye Terminator v3.1 (Applied Biosystems) according to the manufacturer’s protocol, or by allelic discrimination using a TaqMan Custom SNP Genotyping Assay (Applied Biosystems) as previously described.15 (link)