Used primarily in the treatment of non-small cell lung cancer (NSCLC), especially in patients with specific epidermal growth factor receptor (EGFR) mutations. It functions as a tyrosine kinase inhibitor, blocking signals that promote tumor growth, thereby slowing or stopping cancer progression. Commonly prescribed in oral form, it offers a targeted therapy option with fewer side effects compared to traditional chemotherapy. Often used in first-line treatment for advanced NSCLC when mutation status is confirmed.