Cytokines (CK) are low molecular weight soluble proteins induced by immune agents, mitogens, or other stimulants, produced by various cells with functions including regulating innate and adaptive immunity, hematopoiesis, cell growth, APSC pluripotent cells, tissue repair, etc. Cytokines can be categorized into interleukins, interferons, tumor necrosis factor superfamily, colony-stimulating factors, chemokines, growth factors, etc. These multifunctional cytokines exert their effects through paracrine, autocrine, or endocrine pathways, exhibiting pleiotropy, redundancy, antagonism, synergy, among other physiological characteristics, forming a complex cytokine regulatory network involved in various important physiological functions in the human body.
Cytokines play crucial roles in the development, differentiation, immune responses, and immune regulation processes of immune cells. However, they can also act as a double-edged sword and under certain conditions participate in the onset of various diseases. For example, during immune responses, immune cells secrete large amounts of cytokines, which in turn stimulate immune cells. If this positive feedback regulation fails, it can lead to a "cytokine storm." "Cytokine storms" can occur in various diseases such as acute respiratory distress syndrome, SARS (severe acute respiratory syndrome), and influenza, among others.
