CHO cells, or Chinese Hamster Ovary cells, are a type of cell line commonly used in biological and medical research. They are derived from the ovary of the Chinese hamster and are favored for their ability to grow rapidly and produce proteins. CHO cells are particularly important in the production of therapeutic proteins, including monoclonal antibodies. These cells are often genetically modified to enhance their productivity and stability. Due to their ability to perform post-translational modifications similar to human cells, CHO cells are widely used in the pharmaceutical industry for the development of vaccines and other biologics.