Crisaborole (AN-2728) inhibits PDE4, TNF-α, IL-2, IFN-γ, IL-5 and IL-10 with IC50 values of 0.49, 0.54, 0.61, 0.83, 2.4 and 5.3 μM. Crisaborole (AN-2728) shows the most potent activity against PDE4 catalytic domain, but it also shows inhibition against PDE1A3, PDE3Cat, and PDE7A1. Crisaborole (AN-2728) inhibits PDE isozymes PDE1A3, PDE3Cat , PDE4Cat and PDE7A1 with IC50 values of 6.1, 6.4, 0.11 and 0.73 μM. Crystallography reveals that interaction of benzoxaboroles with the hydrophobic pocket in the PDE4 catalytic domain increase their affinity for PDE4. These benzoxaboroles strongly suppresses the secretion of cytokines associated with Ps and AD. Crisaborole (AN-2728) is a topically administered, boron-containing, anti-inflammatory compound that inhibits PDE4 activity and thereby suppresses the release of TNFalpha, IL-12, IL-23 and other cytokines.