Another advantage of PDE4 PROTACs over conventional inhibitors is the longevity of action, as once inside the cell, the degrader sequentially eliminates PDE4 targets to ensure lack of rescue via transcriptional upregulation, as seen for drugs such as Roflumilast when used for chronic obstructive pulmonary disease (COPD) [42]. The gene discussed is PDE4A; the disease is chronic obstructive pulmonary disease.