We study the role of the rhombic lip as a key organiser of the development of both neural and non-neuronal structures in the hindbrain. We are interested in this epithelia interface not only as a source of cells in the cerebellar and pre-cerebellar circuit but also as a signalling centre that orchestrates cell behaviour and fate in adjacent tissue. Neurons produced at the rhombic lip include granule cells but also deep nuclei that establish connectivity with other brain regions. These latter populations mediate the role of the cerebellum beyond movement control and as a key regulator of cognitive function. Both granule cell number and connectivity are highly variable across different vertebrates. We therefore see a comparison of genetic and cellular aspects of rhombic lip in different animals as an important experimental approach to understanding its fundamental properties in human development.