Apical polarization and lumenogenesis: The apicosome sheds new light.

Establishment of apico-basal polarity is critical for the lumenal epiblast-like morphogenesis of human pluripotent stem cells (hPSCs). In this issue, Taniguchi et al. (2017. J Cell Biol. https://doi.org/10.1083.jcb201704085) describe a structure called the apicosome, generated in single hPSCs, that allows them to self-organize and form the lumenal epiblast-like stage.