Telomerase-IN-9 is a potent and selective inhibitor of telomerase, effectively reducing telomerase activity by binding to hTERT, which results in diminished telomerase function. This compound induces apoptosis and inhibits colony formation. It has been shown to reduce tumor burden, restore antioxidant balance, and protect lung structure in a mouse model of lung cancer induced by Benzo[a]pyrene. Telomerase-IN-9 is applicable in lung cancer research.