The world’s largest lung health conference, commonly known as “The Union” conference. This annual forum (spanning five days at the Bella Center Copenhagen) attracts thousands of delegates, including researchers, policymakers, and public health experts. While historically focused on tuberculosis, the conference now covers all lung health issues, including COPD, asthma, tobacco control, air pollution, and lung infections. Sessions address global and regional strategies to combat respiratory diseases, featuring the latest research findings and policy debates. The 2025 Union Conference is expected to highlight links between infectious diseases and chronic respiratory illnesses, and to host advocacy events (e.g., for clean air and smoking cessation) in conjunction with scientific sessions.