The four investigated PDE4D crystal complexes have all been shown to be antagonists of PDE4D functions, thus the DCT-compounds docked with them (Table 1) present the potential to reduce bronchoconstriction and reduce the asthma inflammatory cellular mediated symptoms (Billington et al., 2013; Raker, Becker & Steinbrink, 2016; UniProt). This evidence concerns the gene PDE4D and asthma.