Additionally, the complexity of APIs can be illustrated with Biologic APIs, such as Monoclonal Antibodies. These are larger, more complex molecules produced using living organisms. One prominent example is Trastuzumab (Herceptin), used in targeted cancer therapy. Its development represents a significant advance in the treatment of HER2-positive breast cancer. Unlike traditional small-molecule APIs, biologic APIs require advanced techniques, including genetic engineering and cell culture technologies, making their production a highly sophisticated endeavor.