How evolution made the matrix punch at the multicellularity party.

The basement membrane is a specialized sheet-like form of the extracellular matrix that provides structural support to epithelial cells and tissues, while influencing multiple biological functions, and was essential in the transition to multicellularity. By exploring a variety of genomes, Darris et al. provide evidence that the emergence and divergence of a multifunctional Goodpasture antigen-binding protein (GPBP), a basement membrane constituent, played a role in this transition. These findings help to explain how GPBP contributed to the formation of these extracellular matrices and to more precisely define the transition to multicellular organisms.