Abstract

Cytokines are small signaling proteins that play a crucial role in the regulation and coordination of immune and inflammatory responses. Produced by a wide variety of immune and non-immune cells, cytokines act as messengers that mediate intercellular communication, influencing cell proliferation, differentiation, migration, and apoptosis. This article explores the classification and functions of major cytokine families, including interleukins, interferons, tumor necrosis factors, and chemokines. It also highlights the dual roles of cytokines in promoting and resolving inflammation, as well as their involvement in the pathogenesis of diseases such as autoimmune disorders, infections, and cancer. Special emphasis is placed on the mechanisms by which cytokines regulate immune responses and how dysregulation can lead to pathological conditions, such as cytokine storms observed in severe viral infections. Finally, current therapeutic strategies targeting cytokines and their receptors are discussed, illustrating their importance in modern immunotherapy and clinical medicine.