This works particularly well for cancers with recurring mutational patterns (like KRAS mutations in pancreatic cancer), since that lets you affordably do ultra-

This works particularly well for cancers with recurring mutational patterns (like KRAS mutations in pancreatic cancer), since that lets you affordably do ultra-deep sequencing of small regions of the genome. If you had to deep (>5000x coverage) sequencing of many megabases then (with currently available platforms) the diagnostic wouldn't be affordable.