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. The gene discussed is IL24; the disease is Alzheimer disease.