On the other hand, the ATM/ATR‐mediated activation of the tumor suppressor p53 was shown to occur in a nucleolus exposed to nucleolar stresses, such as a treatment with CX‐5461, an inhibitor of RNA polymerase I [20], suggesting that the nucleolar stresses caused by the disruption of ribosome biogenesis may be targets for cancer therapy [21]. Here, TP53 is linked to cancer.