At least three types of FDA-approved anti-cancer agent were found to also suppress rRNA synthesis: (i) Temsirolimnus/everolimus (mTOR inhibitors) inhibit RNA Pol I transcription [27], (ii) topotecan/irinotecan modulate early rRNA processing [28], and (iii) 5-fluorouracil (5-FU) impairs late rRNA processing [29]. The gene discussed is MTOR; the disease is cancer.