PTC-209 is primarily used in research settings to study cancer biology, particularly in the context of tumor growth and stem cell regulation. It functions as a selective inhibitor of BMI-1, a protein involved in the self-renewal of cancer stem cells. By targeting BMI-1, PTC-209 helps researchers investigate the mechanisms behind cancer progression and resistance to therapies. This chemical is valuable in preclinical studies aimed at developing new strategies to inhibit cancer stem cells, which are often responsible for tumor recurrence and metastasis. Its application is crucial in advancing understanding of potential therapeutic targets for various cancers, including leukemia, breast cancer, and glioblastoma.