Monoclonal antibodies are laboratory-made molecules designed to mimic the immune system's ability to fight off harmful pathogens like viruses and bacteria. They are created by cloning a single type of immune cell, which produces identical antibodies that target a specific antigen. This makes them highly effective for treating various diseases, including some types of cancer and autoimmune disorders. These antibodies can be used in diagnostics and therapies, helping doctors identify diseases or deliver targeted treatments. For example, Rituximab is a monoclonal antibody used to treat certain blood cancers, showcasing the potential of these powerful tools in modern medicine.