Targeted therapies work by interfering with specific molecules involved in tumor growth and progression. These therapies can be classified into several types, including monoclonal antibodies, small molecule inhibitors, and immunotherapies. Monoclonal antibodies are designed to bind to specific antigens on the surface of cancer cells, blocking their growth. Small molecule inhibitors, on the other hand, penetrate the cell membrane to interact with targets inside the cell, disrupting essential processes such as signal transduction. Immunotherapies enhance the body's own immune response to recognize and destroy cancer cells.