The preferential expression of PDE8A protein in the CD4+ T cell subset during the acute AAD stage and its subsequent recession in the non-inflammatory tolerant stage, together with the common assumption that CD4+ Teff cells are a major contributor to the development of AAD in animals and asthma in humans, strengthen the case to further examine PDE8A inhibition in preclinical and clinical studies of inflammatory disorders, including human respiratory airway diseases. Here, CD4 is linked to asthma.