PDE4B inhibitors: PDE4B inhibition is associated with anti‐inflammatory and antifibrotic properties.[577] BI1015550 is an oral preferential inhibitor of PDE4B.[578] A phase II clinical trial demonstrated that treatment with BI1015550, either alone or in combination with antifibrotic agents, alleviated the decrease in pulmonary function in patients with IPF (NCT04419506).[579] Multiple phase III trials are ongoing to further evaluate its efficacy and safety in IPF (NCT06238622, CTR20242619). This evidence concerns the gene PDE4B and idiopathic interstitial pneumonia.