Chinese Hamster Ovary (CHO) cells are a type of cell line derived from the ovaries of the Chinese hamster, specifically the species Cricetulus griseus. These cells are widely used in biological and medical research, particularly for producing recombinant proteins and studying cellular processes. CHO cells are favored in biotechnology because they can grow in suspension and are capable of post-translational modifications, which are essential for the proper functioning of many proteins. They play a crucial role in the development of therapeutic drugs, including monoclonal antibodies and vaccines.