Gleevec, also known as imatinib, is a medication primarily used to treat certain types of cancer, particularly chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GISTs). It works by inhibiting specific proteins that promote the growth of cancer cells, effectively slowing down or stopping their proliferation. Approved by the U.S. Food and Drug Administration (FDA) in 2001, Gleevec has significantly improved the prognosis for patients with these conditions. It is taken orally and is often well-tolerated, allowing many patients to maintain a good quality of life while managing their disease.