T cells during breakthrough acute GVHD display a prosurvival and Th17-skewed phenotype. (A) Flow cytometric analysis of PBMCs measured for the expression of Bcl-2. Plots depict the percentages of CD4 and CD8 T cells expressing Bcl-2. *P < .05 using analysis of variance (ANOVA) with Tukey multiple comparison test. (B) Bar plot of fold-change expression values (log₂ normalized) for transcripts in breakthrough acute vs suppressed samples that meet differential expression cutoffs (fold change > 1.3 and P < .05 using a moderated t statistic corrected using the Benjamini procedure.) Red bars, Antiapoptotic transcripts. Blue bars, Proapoptotic transcripts. Gray bars, Genes with other functional attributes. (C) Scatter plot of fold-change expression values (log₂ normalized) of breakthrough acute vs healthy controls (HCs) (x-axis) and hyperacute vs healthy controls (y-axis). Blue points denote those transcripts whose expression is above threshold values (log₂ fold change < 0.5, and P < .05 using a moderated t statistic corrected using the Benjamini procedure) and whose expression in both breakthrough acute and hyperacute samples is overrepresented or underrepresented relative to healthy controls. Red points denote pivot transcripts, whose expression meets cutoffs noted above, and whose differential expression in breakthrough acute and hyperacute samples compared with healthy controls are in opposite directions. (D) Heatmap showing the expression levels of inflammatory Tc17-related genes identified in a study of fate-mapped murine Tc17 cells³⁵  in the NHP breakthrough acute GVHD arrays compared with either autologous controls (Auto, left column) or healthy controls (HC, right column). The rows in the heatmap contain 24 genes previously identified as overrepresented (n = 12, top half of heatmap) and underrepresented (n = 12, bottom half of heatmap) in murine Tc17 cells during GVHD relative to controls. One gene (Ly6c1) identified in the murine study was not included in this analysis, as it has no human/NHP ortholog.³⁶  The columns reveal the expression of these genes in the breakthrough acute cohort vs either autologous (left) or healthy controls (right). The column to the right of the gene names designates whether the direction of expression in breakthrough acute vs autologous or healthy controls is concordant (gray boxes) or not (white boxes) with the expression in murine Tc17 cells.