UNC-GRK4-V–specific T cells are present post-SCT. UNC-GRK4-V–specific T-cell populations were tested in 12 HLA-A*02:01–expressing AML patients who had undergone allo-SCT. Negative tetramers were used for each sample to define tetramer-positive gates for each patient. (A-C) Three patients in DRPs with gMMs for UNC-GRK4-V were tested, with 1 patient (A, alive 29 months post-SCT with chronic GVHD) showing an expanded tetramer-positive population. (D-I) Six patients in DRPs where both the recipient and donor carried the UNC-GRK4-V allele were tested, and 3 patients (D, alive 75 months post-SCT with mild chronic GVHD; E, died of relapsed AML 21 months post-SCT; F, alive 84 months post-SCT without GVHD) showed evidence of a tetramer-positive population. (J-L) Three patients in DRPs in which the patient did not carry the UNC-GRK4-V allele were tested, and no samples showed a tetramer-positive population.