ANGPT2 and capillary leak syndrome: Given the pathophysiological differences between classical and ICI-induced CLS, future research should focus on identifying predictive biomarkers (e.g., vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2), or intercellular adhesion molecule-1 (ICAM-1)), clarifying immune mechanisms behind endothelial injury, and establishing evidence-based treatment algorithms.