Consequently, anticancer drugs targeting TOP1 are highly toxic for fast dividing cells, such as cancer cells, and are clinically used in treatment of, e.g., colon cancer, ovarian cancer, and small cell lung cancer [33,34,35], where lethal TOP1cc is introduced by analogues of the small molecule, camptothecin (CPT) [36,37,38]. The gene discussed is TOP1; the disease is cancer.