Expression profiling reveals T-cell exhaustion as a strongly associated signature of response to DLI therapy. Differential gene expression from CD3⁺ T cells isolated from the marrow of DLI responders (R) and nonresponders (NR) before DLI therapy (A) or in response to treatment (B). The annotation of genes within key biological processes is indicated. The asterisks refer to genes selected for qPCR validation (see C-D). (C-D) qPCR validation of changes in microarray gene expression in selected genes (C) differentially expressed between R and NR before therapy and (D) differentially affected by DLI over time in R compared with NR. Data are represented as mean ±SEM, with each sample performed in triplicate. (E-F) GSEAs from the pretreatment and response to treatment comparisons. The bar graphs show P value of enrichment (signed according to enrichment score) for distinct T-cell exhaustion gene sets in R vs NR before (E) or after (F) DLI therapy. Detailed descriptions of gene sets are provided in supplemental Table 4. The shaded region indicates P > .05.