Identification and Characterization of Relapse-Specific Somatic Mutations. Emergence of relapse-specific PRPS1 mutations during remission, as detected by ultra-deep sequencing (mean, 250,000 reads). Key indicates sample ID of specific study individuals and their respective PRPS1 mutations.Reprinted by permission from Macmillan Publishers Ltd: Nat Med. 2015;21:563-571, copyright 2015.