Interferons are a group of naturally occurring proteins that are produced by the body's cells as a response to viral infections, tumors, and other environmental stimuli. These proteins play a critical role in the body's immune system, helping to activate immune cells and prevent the spread of infectious agents. While interferon is the most commonly used term, there are several other synonyms that have been used to describe these proteins, including cytokines, lymphokines, and immunoregulatory proteins. These terms all refer to the same group of proteins and are used interchangeably in scientific literature. Regardless of the term used, interferons are crucial for maintaining the body's immune defenses and are an important target for research in the field of immunology.