High-resolution mRNA expression change from HDACi therapy. (A) UMAP projection of CD3⁺ T-cell clusters. (B) Relative percentage of flow-sorted malignant (CD3⁺CD4⁺CD5^brightSSC^hi) and nonmalignant (CD3⁺CD4⁺CD5^intSSC^int) T cells by cluster and relative percent of clusters by initial sample collection (T1) and 9 months later on HDACi therapy (T2). (C) UMAP projection with the frequency of TCR V(D)J-based clonotype attached into the following grouping: hyperexpanded (200 < X ≤ 15 100), large (20 < X ≤ 200), medium (5 < X ≤ 20), small (1 < X ≤ 5), and single copies (X = 1) using the scRepertoire R package²² with the percentage of cells in each clonotype category in the lower bar chart. (D) Percent of cells expressing selected common markers for CTCL across the UMAP projection. (E) Volcano plot of differential genes based on the comparison of T2 vs T1 malignant T cells. Significant genes, as defined by 1 > log-fold change < −1 and Bonferroni P value < .05, highlighted in colors. (F) Violin plots relative mRNA expression of selected immune, epigenetic, and resistance factor genes for T1 and T2 malignant cells. (G) Violin plots of ssGSEA enrichment of selected metabolic gene sets for T1 and T2 malignant cells.