Review of the potential value of serum interleukin levels as prognostic biomarkers of liver failure

Figure 1 Mechanism of interleukin 21 in liver failure (diagram depicts various immune cells, including CD4+ T cells, natural killer cells, B cells, T cells, and dendritic cells, along with their interactions and functions). The central role of interleukin 21 (IL-21) is highlighted, as it is secreted by CD4+ T cells and influences the differentiation of B cells into plasma cells, leading to immunoglobulin production, while also inhibiting T cell survival and generation. Additionally, IL-21 can stimulate dendritic cells to induce apoptosis, further impacting the immune response). APC: Anaphase-promoting complex; IFN-γ: Interferon gamma.