Intrapatient and interpatient heterogeneity of CLL cell subpopulations. (A) UMAP of reclustered healthy B/CLL cells (from Figure 1C) from patients and healthy controls. (B) UMAP plots colored by median protein expression of CD20, pS6, and MCL-1, distinguishing between healthy B cells (CD20^high pS6^high MCL-1^low) and CLL cells (CD20^lowpS6^lowMCL-1^high). (C) UMAP plots colored by protein expression level of IgM, distinguishing IgM^high and IgM^low B cells. (D) UMAP plots colored by amounts of pRB, TACI, BAX, and pH2AX, thereby distinguishing between 2 minor subpopulations of CLL cells, namely pRB^highTACI^highBAX^high (cluster 2.9) and pH2AX^high (cluster 2.10). (E) UMAP plots colored by protein expression of CD5, CXCR4, and BCL-2, thereby distinguishing 2 main subpopulations of CLL cells, namely CD5^highCXCR4^lowBCL-2^high (cluster 2.6) and CD5^lowCXCR4^highBCL-2^v.high (cluster 2.7). (F) Representative 2-dimensional plot of CXCR4 vs CD5 expression showing CD5^highCXCR4^low and CD5^lowCXCR4^high CLL cell populations from patient CLL20. (G) Violin plots showing the mean intensities of BCL-2, BCL-XL, MCL-1, pH3, and IgM of old and new CLL cells that have low, medium, and high levels of CXCR4 protein. (H) Frequency of each cluster in the PB of patients before venetoclax treatment. Student paired t test was used. ∗∗∗P < .005; ∗∗∗∗P < .001. BAX, BCL-2 associated protein X; HC, healthy control; pH2AX, phosporylated histone H2AX; pRB, retinoblastoma protein; TACI, transmembrane activator and CAML interactor.