Anthracycline antibiotics are a class of chemotherapy drugs used primarily to treat various types of cancer, including leukemia and breast cancer. They work by interfering with the DNA in cancer cells, preventing them from dividing and growing. Common examples include doxorubicin and daunorubicin. These drugs are derived from the bacterium Streptomyces and are known for their effectiveness but also for potential side effects, such as heart damage and nausea. Due to their potency, anthracyclines are often used in combination with other treatments to enhance their effectiveness against tumors.