List of Interleukins - **IL-1α / IL-1β** – Strongly pro-inflammatory; induce fever, acute-phase response, endothelial activation, and help drive Th17 responses. - **IL-2** – Classic T-cell growth factor; promotes effector T-cell proliferation and is essential for regulatory T-cell (Treg) survival and immune tolerance. - **IL-3** – Early hematopoietic growth factor; supports proliferation and differentiation of myeloid progenitors. - **IL-4** – Drives Th2 differentiation; promotes B-cell class switching to IgE and contributes to allergy and helminth responses. - **IL-5** – Key for eosinophil growth, activation, and survival; important in allergic and helminth immunity. - **IL-6** – Major acute-phase and inflammatory cytokine; promotes B-cell maturation and systemic inflammatory effects. - **IL-7** – Critical for T- and B-lymphocyte development and survival. - **IL-8** – Neutrophil chemoattractant; recruits and activates neutrophils at inflammatory sites. - **IL-9** – Supports T-cell and mast-cell responses; has roles in asthma and mucosal immunity. - **IL-10** – Central anti-inflammatory and immunoregulatory cytokine; suppresses Th1 and Th17 responses and inhibits macrophage cytokine production. - **IL-11** – Supports megakaryocyte and platelet-related effects and contributes to mucosal protection. - **IL-12** – Promotes Th1 differentiation and IFN-gamma production; bridges innate and adaptive immunity against intracellular pathogens. - **IL-13** – Works with IL-4 in type 2 immunity; promotes mucus production, airway hyperreactivity, and IgE-associated responses. - **IL-14** – B-cell growth factor involved in B-cell proliferation and antibody responses. - **IL-15** – Essential for NK-cell development and memory CD8 T-cell survival. - **IL-16** – Chemoattractant for CD4-positive cells. - **IL-17** – Signature Th17 cytokine; drives neutrophilic inflammation and is implicated in autoimmunity. - **IL-18** – Boosts IFN-gamma production and cooperates with IL-12 to promote Th1 responses and NK-cell activation. - **IL-19** – Regulatory cytokine involved in inflammatory responses, especially in skin and epithelial tissues. - **IL-20** – Acts on keratinocytes; involved in skin inflammation and keratinocyte proliferation. - **IL-21** – Potent T- and B-cell helper cytokine; supports plasma cell differentiation and modulates NK and CD8 T cells. - **IL-22** – Acts on epithelial cells to promote barrier integrity, antimicrobial peptide production, and tissue repair. - **IL-23** – Maintains Th17 cells and IL-17 production; central to chronic inflammatory diseases. - **IL-24** – Has tumor-suppressive, wound-healing, and inflammatory skin-related functions. - **IL-25** – Promotes type 2 immunity, enhancing IL-4, IL-5, and IL-13 production and eosinophilic inflammation. - **IL-26** – Amplifies local inflammatory responses, especially in mucosal tissues. - **IL-27** – Has mixed roles; can promote early Th1 differentiation and also exert regulatory anti-inflammatory effects. - **IL-28** – Important in antiviral defense at epithelial barriers. - **IL-29** – Also involved in antiviral and host defense responses at epithelial surfaces. - **IL-30** – Functions as part of IL-27 or independently to modulate T-cell responses. - **IL-31** – Associated with pruritus and inflammatory skin disease such as atopic dermatitis. - **IL-32** – Pro-inflammatory cytokine that can induce TNF, IL-1, and IL-6 from monocytes and macrophages. - **IL-33** – Alarmin released on cell damage; drives type 2 responses and contributes to allergy and asthma. - **IL-34** – Supports monocyte, macrophage, and microglial survival and differentiation. - **IL-35** – Strong immunosuppressive cytokine that inhibits effector T-cell proliferation. - **IL-36** – Activates dendritic cells and T cells in skin and mucosa; contributes to psoriasis-like inflammation. - **IL-37** – Broad anti-inflammatory cytokine that dampens innate and adaptive immune responses. - **IL-38** – Anti-inflammatory cytokine that limits excessive inflammation.