This novel observation, together with published evidence of chemotaxis activity by IL-17 on airway smooth muscle cells [23], suggests the possibility that other structural or innate/adaptive immune cells could display chemotactic response to Th-17-derived cytokines; if this hypothesis is true, the impact of Th-17 cytokines in asthma pathophysiology and in other chronic inflammatory diseases could have been underestimated. This evidence concerns the gene IL17A and asthma.