Lineage tracing of stem cells decades after blood and bone-marrow transplantation

In individuals receiving an allogeneic haematopoietic cell transplant, stem cells in the bone marrow, which give rise to blood and immune cells, are replaced with those from a donor. Genome-sequencing analyses in donor–recipient pairs years after transplantation show an accelerated loss of clonal diversity in the blood stem cells of recipients compared with those of donors. The clonal dynamics of haematopoietic stem cells after transplantation vary according to the ages of the donor and the recipient.