EPO and asthma: Furthermore, many cross-sectional studies have examined the inflammatory markers associated with clinical and complete asthma remission in different samples such as blood, sputum, BALF, or endobronchial biopsies and eosinophils, neutrophils, mast cells, IgE, FeNO, iNOS, histamine, ECP, and EPO (214, 218–222).