Forgotten Foundations: Basement Membranes in Lung Function and Cancer

The basement membrane is a specialised extracellular matrix network that orchestrates fundamental cellular processes in many organs. In the lung, this dynamic scaffold provides compositionally encoded instructions that direct epithelial differentiation, regulate injury responses, and modulate disease progression. Despite its fundamental importance, the basement membrane remains an understudied aspect of lung biology, with its precise composition, spatial organisation and biomechanical properties in health and disease poorly defined. This review synthesises current understanding of lung epithelial basement membrane composition and function with emphasis on how this matrix layer supports lung development, injury repair, and cancer progression. We highlight evidence that basement membrane components are not merely structural supports but active regulators of cellular phenotype and discuss how this conceptual shift opens new therapeutic strategies in lung cancer.