IL-7(Interleukin-7) is a cytokine important for B and T cell development. IL-7 plays a crucial role in the immune system, primarily by promoting the survival and proliferation of lymphocytes, particularly T cells and B cells. IL-7 is located in the extracellular space and is secreted by stromal cells in the bone marrow and thymus, where IL-7 binds to IL-7 receptor on target cells. This interaction is vital for lymphocyte development and homeostasis, as IL-7 not only supports the survival of immune cells but also influences differentiation and function. IL-7 receptor is a heterodimer composed of an IL-7 receptor-specific chain and the common gamma chain, which is shared with other interleukin receptors. Dysregulation of IL-7 signaling has been implicated in various immunological disorders, including autoimmune diseases and lymphoid malignancies, making IL-7 a significant target for therapeutic interventions.