IL5 and Increased total eosinophil count: Due to the emergence of biologics targeting the Th2 axis by blocking IL-4 and IL-13 (e.g., with dupilumab) or IL-5 signaling (e.g., with mepolizumab and benralizumab), understanding the mechanism of eosinophilia in the lung transplant setting is of great importance to act as the basis for bringing these drugs into use in novel indications such as chronic allograft dysfunction.