We found that PDE4B-expressing DLBCLs display higher SYK-BTK-PIK3 activity downstream of the B-cell receptor (BCR), and that the FDA-approved PDE4 inhibitor (PDE4i) roflumilast (https://pubchem.ncbi.nlm.nih.gov/compound/Roflumilast, accessed on 6 November 2024) suppresses these signals and promotes lymphoma cell death [7,10,11,12,13]. The gene discussed is PDE4A; the disease is lymphoma.