Previously, we have shown that 7-hydroxycoumarin derivatives with monoterpene moieties 11 and 12 (Figure 2) inhibit TDP1 in the submicromolar concentration range and sensitize the action of camptothecin (a Top1 inhibitor of natural origin) [29] and topotecan on the Krebs-2 ascites in vivo tumor model [30]. This evidence concerns the gene TDP1 and neoplasm.