Used in research for targeted cancer therapies, particularly as an irreversible inhibitor of EGFR (epidermal growth factor receptor) and HER2, which are proteins involved in tumor growth. Shows potential in suppressing the proliferation of cancer cells in breast, lung, and gastric cancers. Often studied in preclinical models to evaluate efficacy and mechanism of action in overcoming resistance to other EGFR inhibitors. The tosylate (TsOH) form improves solubility and stability, making it suitable for in vitro and in vivo studies. Not approved for clinical use but valuable in oncology drug development.