TP53 and neoplasm: Collectively, although endogenous SBDS is essential for rRNA synthesis in the nucleolus28 and for ribosome assembly in the cytoplasm29, which may confer its oncogenic activity in cancer (Figs. 1–4), ectopic SBDS in the nucleoplasm plays a tumor-suppressive role in part by activating p53 (Figs. 5–8).