Transcriptomic changes during therapy with pirtobrutinib. Cells were isolated from patients’ peripheral blood samples (n = 18), which were collected before treatment with pirtobrutinib (C1D1) and at the indicated time points (C1D8, C2D1, and C4D1). Transcript levels in the samples were quantified using RNA sequencing. Significant differences were defined as an FDR of 0.05 and log fold change >2. (A) A likelihood ratio test was performed to identify genes that were significantly differentially expression at the assessed time points during therapy with pirtobrutinib in the BTK-WT and BTK-mutated groups separately. The heat map shows significantly differentially expressed genes (FDR < 0.01) that were shared between the WT and mutated BTK groups. The thick white line separates the WT and mutated groups, and the numbers on the x-axis correspond to the patient numbers in Table 1. (B-C) Bubble charts illustrating a comparison of Hallmark pathway enrichment analyses at time points C1D8, C2D1, and C4D1 with reference to baseline (C1D1) in the BTK-WT group (B) and the BTK-mutated group (C). Enrichment scores for the signaling pathways are indicated by the colors, whereas FDR values are represented by the size of the bubbles.