Mini reviewsThe nature and biology of basement membranes

- Basement membranes have reached center stage due to their involvement in many physiological and pathological conditions.
- Genetic diseases of basement membranes are debilitating and affect many organs resulting in diverse phenotypes.
- We provide an overview of the field and discuss developmental, structural and biochemical aspects of basement membranes.
- We introduce the special issue and outline key components of basement membrane biology.

Basement membranes are delicate, nanoscale and pliable sheets of extracellular matrices that often act as linings or partitions in organisms. Previously considered as passive scaffolds segregating polarized cells, such as epithelial or endothelial cells, from the underlying mesenchyme, basement membranes have now reached the center stage of biology. They play a multitude of roles from blood filtration to muscle homeostasis, from storing growth factors and cytokines to controlling angiogenesis and tumor growth, from maintaining skin integrity and neuromuscular structure to affecting adipogenesis and fibrosis. Here, we will address developmental, structural and biochemical aspects of basement membranes and discuss some of the pathogenetic mechanisms causing diseases linked to abnormal basement membranes.