CD19 and cancer: This finding is in accordance with previous reports showing that leukaemic cancers often exhibit multiple centrosomes.32, 33 Interestingly, when we performed transient siRNAmediated knockdown of TP53 in healthy donor CD19+ cells (Figure 6 and Supporting Information), we could show that knockdown of TP53 resulted in a phenotype that highly resembled CLL cells with multiple centrosomes and accumulation of cells arrested in cytokinesis.