Matrix interactions regulate epithelial polarity and cohesion in the second heart field.

Addition of epithelial progenitor cells drives progressive extension of the heart tube during cardiac morphogenesis. In this issue of Developmental Cell, Arriagada et al. (2024) refine our understanding of how these cells condition and interact with the underlying extracellular matrix, demonstrating that autonomous fibronectin synthesis controls their apicobasal polarity and deployment to the heart.