Adoptively transferred CTLs migrate to bone marrow but have limited in vivo persistence. (A) Real-time PCR with primers that specifically amplify the uniquely rearranged TCRβ CDR3 region of the mHAg-specific CTL clone 11B9-45 were used to detect and enumerate 11B9-45 CTL in the blood (■) and bone marrow (BM; ▩) of Patient no. 7 at the indicated time points before or during T-cell therapy. The level of 11B9-45 CTLs detected is expressed as a percentage of PBMCs or bone marrow mononuclear cells (BMMCs). The dose (in approximate log₁₀ scale) and timing of each of the 4 T-cell infusions administered to this patient (Tx1, Tx2, Tx3, and Tx4) are indicated. (B) Flow cytometric analysis of 11B9-45 CTLs before adoptive transfer. Cells stained with a mAb specific for the molecule indicated to the right of each histogram are indicated in red, and those stained with an isotype control antibody are indicated in green.