IL21

IL21 is a cytokine secreted by immune cells such as CD4+ T cells and NK cells. It activates the JAK/STAT signaling pathway by binding to its specific receptor, IL-21R, thereby regulating the cell proliferation, differentiation, and function. IL21 is particularly important in anti-tumor immunity, as it enhances the anti-tumor activities of T cells and NK cells while promoting B cell production of specific antibodies, thus bolstering humoral immunity. Additionally, IL21 plays a significant role in autoimmune diseases, with abnormal expression potentially triggering autoimmune reactions. Understanding IL21's functions and regulatory mechanisms can provide valuable insights into both reproductive physiology and tumor pathology.