Alkylating agents are a class of chemicals that can add alkyl groups to DNA, which can interfere with the cell's ability to divide and grow. They are commonly used in chemotherapy to treat various types of cancer, as they can damage the DNA of rapidly dividing cancer cells, leading to cell death. These agents work by forming covalent bonds with DNA, causing mutations that prevent proper replication. Some well-known alkylating agents include cyclophosphamide and melphalan. While effective against cancer, they can also affect healthy cells, leading to side effects such as nausea and increased risk of infection.