As previously [169] stated, during the 1990s, PDE4 might participate in viral infections, since the PDE4 inhibitor, rolipram, was canonically shown to inhibit human immunodeficiency virus-1 (HIV-1) replication, and to decrease HIV-1 p24 antigen production in acutely HIV-1 infected PBMCs [170]. Here, PDE4A is linked to viral infectious disease.