To comprehensively characterize the longitudinal phenotypic changes in CD8+ T cells in KTRs experiencing CMV primary infection or reactivation, we performed single-cell RNA sequencing (scRNA-seq) on purified peripheral blood CD8+ T cells collected at pre-viremia baseline (BL, approximately 3-months post-Tx), 1-week post-viremia (1W), and long-term (LT, approximately 1-year post-Tx) from a selected cohort of R- (n=4) and R+ (n=4) KTRs (Table 1). The gene discussed is CD8A; the disease is infection.