Used in chemotherapy for treating certain types of cancer, including breast cancer, leukemia, and non-Hodgkin’s lymphoma. It works by interfering with DNA replication and RNA synthesis in rapidly dividing cells. Also used in the management of multiple sclerosis to reduce neurological disability and frequency of relapses by suppressing immune system activity. Administered intravenously under medical supervision due to potential side effects like cardiotoxicity and myelosuppression.