A protein family is a group of proteins that share a common evolutionary origin, structure, or function. These proteins often have similar amino acid sequences and perform related biological roles within an organism. For example, the globin family includes proteins like hemoglobin and myoglobin, which are involved in oxygen transport and storage. Proteins within a family can vary in their specific functions and properties, allowing them to adapt to different biological contexts. Researchers study protein families to understand their roles in health and disease, as well as to develop targeted therapies and drugs.