By transferring a donor-derived, expanded CD57⁺ 27⁻ CD4⁺ T-cell population from a CMV-seropositive donor that further expands in the allograft recipient, T-cell inflation is induced with a reduced TCR repertoire and a depletion of donor APCs. This result increases the risk of secondary infections and transplant-related mortality. Professional illustration by Patrick Lane, ScEYEnce Studios.