Many of the pretransplantation CMV-specific T-cell clones expanded after transplantation. Lanes show the PCR products of the depicted variable regions of the Vβ-chain (BVs) used by CMV-specific, tetramer-positive (TET+) and CD8⁺, tetramer-negative (TET-) T cells before and at day 97 after transplantation. Spectratypes of BV14, the BV of the TCR predominantly used by the tetramer-positive T cells after transplantation, are shown on the right.