TP53 and B-cell chronic lymphocytic leukemia: Previous studies performing RNAi‐mediated knockdown linked reduced NuMA protein levels to reduced CDKN1A (p21) mRNA expression levels, while it does not affect expression of TP53 regulated pro‐apoptotic genes.28, 29 We also showed that CDKN1A expression levels were reduced in CLL compared to healthy donor samples, while pro‐apoptotic genes such as TP53I3, ING4 and ING5 were increased.