Updated project metadata. The mucus secreted by airway epithelial cells plays a key role in the protection against and clearance of particles and pathogens. In this project, a 3D model of the bronchial epithelium was established using Calu-3 cells grown on porous inserts at the air-liquid interface. The secreted proteins were characterized in long-term cultures and compared to the apical secretome of primary normal human bronchial epithelial (NHBE) cells. The apical secretome was collected and characterized in the Calu-3 model at day 4, day 11, and day 18 after air-liquid interface and in the NHBE model at day 4, day 12, and day 18 after air-liquid interface. "This project received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no 760928 (BIORIMA)."