The concentrations of cytokines such as IL-4, IL-5, IL-13, and TSLP in serum, sputum, and bronchoalveolar lavage fluid (BALF) in asthma have been reported to range from 1 to 100 pg/ml (approximately 0.7–70 pM) [22-27]. This evidence concerns the gene TSLP and asthma.