To obtain DNA for genotyping, a 10-μm section from blocks containing formalin-fi xed, paraffi n-embedded tissues was deparaffi nized with xylene and washed twice with absolute ethanol. After residual ethanol evaporated, tissues were digested overnight at 56°C in 200 μL Buffer PKD with 20 μL proteinase K (QIAGEN, Valencia, CA, USA). Extraction of the supernatant was completed with an EZ1 DNA Tissue Kit or a MagAttract DNA Mini M48 Kit (QIAGEN), with DNA eluted into a fi nal 100-μL volume. DNA quality was assessed with a human RNase P real-time PCR in 25-μL volumes by using Agilent Brilliant II QPCR Master Mix as described (4) . Validated TaqMan assays were used to genotype each SNP (protocols, primers, and probes available at http://snp500cancer.nci.nih.gov). Each 25-μL real-time PCR consisted of 12.5 μL of TaqMan Universal PCR Master Mix (Applied Biosystems, Foster City, CA, USA), 900 nmol of assay-specifi c primer, 200 nmol of assay-specifi c probe, and 5 μL of DNA. All controls (extraction blanks, no template controls, and positive controls for each genotype used at 5 ng per PCR; Coriell Institute for Medical Research, Camden, NJ, USA) and unknown samples were assayed in duplicate. Thermal cycling conditions consisted of 1 cycle at 50°C for 2 min, 1 cycle at 95°C for 10 min, and 50 cycles of 92°C for 30 s and 60°C for 1 min. Data were collected during the annealing plateau.