Tumor genomic DNA was purified from the same sample using the AllPrep DNA/RNA/miRNA kit (QIAGEN) with disruption on a Tissuelyser II (QIAGEN). Whole-exome capture libraries were constructed from 100 ng to 1 µg of DNA from tumor and normal tissue after sample shearing, end repair, and phosphorylation and ligation to barcoded sequencing adaptors. Ligated DNA was size selected for lengths between 200 and 350 bp and subjected to hybrid capture using SureSelect Exome v4 baits (Agilent).