Interleukin-24 in type 2 immune diseases.

Interleukin (IL)-24, a member of the IL-20 cytokine family, is secreted by multiple cell types, such as immune cells (T cells, B cells, NK cells, macrophages), and non-immune cells (epithelial cells and fibroblasts). IL-24 and its downstream signaling pathways mediate vital biological processes, including processes governing cell growth, fate determination, cell death, and inflammation, albeit with effects that are context-dependent across disease states. In this review, we present comprehensive summary and recent breakthroughs in IL-24 characterization and its emerging pathogenic functions in type 2 immune diseases, including chronic spontaneous urticaria (CSU), atopic dermatitis (AD), allergic contact dermatitis (ACD), bullous pemphigoid (BP), chronic nodular prurigo (CNPG), and allergic airway diseases, in an attempt to provide valuable insights for developing its potential as biomarkers or therapeutic targets.