Dr. Peter Campbell is head of cancer, aging, and somatic mutation, senior group leader, and joint head of the Cancer Genome Project at the Wellcome Trust Sanger Institute and is a practicing hematologist at Addenbrooke’s Hospital in Cambridge, in the United Kingdom. Stephen Morrissey, the interviewer, is the Executive Managing Editor of the Journal. J. Nangalia and P.J. Campbell. Genome Sequencing during a Patient’s Journey through Cancer. N Engl J Med 2019;381:2145-2156.