IL13 and asthma: Unfortunately, the lack of functional ciliated cells cannot be compensated, e.g., by higher transportation rates of those that remain intact; on the contrary, the TH2-biased environment in the airways of asthma patients is a rich source of the cytokine interleukin-13 (IL-13), which is not only the main driver of GC-differentiation and mucus production but was also found to further induce aberrant and reduced cilial beating [81,82].