Libraries were prepared using the Roche KAPA HyperPrep Kit with custom dual-indexed sequencing adaptors and molecular barcodes. Tumor and normal samples were initially captured using the IDT xGen Exome Research Panel v2 to identify somatic tumor mutations. Personalized IDT Discovery Pools were designed for each patient to enrich for all SNVs called in at least one tumor region and used for targeted resequencing of the tumor, normal, and plasma samples.