Molecular ontogeny in donor-derived FL. (A) Bone marrow transplantation (BMT) and DLIs were performed for chronic myelogenous leukemia. FL developed concurrently in the recipient and the donor. Sequencing of both FLs identified shared and disparate mutations. (B) Models for subclonal loss of the CTSS mutation from the recipient's FL. (C) Ultra-deep sequencing of sorted populations from the DLI. DNA from the donor's buccal swab (buccal) was used for germline material. *P < .01 versus with buccal for the same mutation.