Used in targeted cancer therapy, particularly for non-small cell lung cancer with specific EGFR mutations. It selectively inhibits mutant forms of EGFR, including the T790M resistance mutation, while sparing wild-type EGFR, reducing side effects. Its irreversible binding allows prolonged suppression of tumor growth. Employed in clinical settings where patients have developed resistance to first-generation EGFR inhibitors. Shows improved efficacy and safety profile in mutation-positive patients, making it a valuable option in precision oncology.