design: Libraries were prepared using the NanoSeq protocol as described in Absacal et al.,2021, "Somatic mutation landscapes at single-molecule resolution". Genomic DNA was purified with AMPure XP beads and eluted in nuclease-free water (NFW). An on-bead fragmentation reaction was performed using the HpyCH4V enzyme (NEB), followed by purification with AMPure XP beads and resuspension in NFW. A-tailing was conducted with 10× NEBuffer 4,  Klenow fragment (NEB), equimolar 1 mM dATP/ddBTPs (ddTTP, ddCTP, ddGTP), and NFW. The full A-tailing product was combined with the ligation mix: 10× NEBuffer 4, 10 mM ATP, 15 µM xGen Duplex Seq Adapters (IDT), T4 DNA Ligase ( NEB), and NFW. Libraries were purified with 1× AMPure XP beads and eluted in NFW. Libraries were quantified using the KAPA Library Quantification Kit (Roche, Cat# KK4824), and input amounts were normalized. Matched normal libraries were sequenced undiluted to support germline SNP filtering. PCR amplification was performed using UDI-containing primers (Paragone Genomics), followed by two consecutive AMPure XP bead cleanups, final quantification, and pooling for sequencing.