Baseline transcriptomic differences between the BTK-WT and BTK-mutated groups of patients with CLL. (A) A PCA plot of baseline RNA sequencing data by BTK mutation status is shown (BTK-WT, n = 7; BTK-mutated [MUT], n = 10). (B) Hallmark pathways enriched at baseline (FDR < 0.05) in the BTK-mutated group when compared with the BTK-WT group. The significantly enriched pathways were metabolism, proliferation, cell signaling, cellular stress response, and other. (C) A heat map of significantly differentially expressed genes in the BTK-WT and -mutated groups at baseline. The numbers on the x-axis correspond to the patient numbers in Table 1. Gene names are provided on the right y-axis.