Major fundamental cell shapes discussed in this review are depicted. All epithelia have a typical ABP, but their morphologies range from flat or squamous, to cuboidal or columnar. Epithelia can either consist of a single cell layer, referred to as simple epithelia, or host multiple cell layers, known as stratified epithelia. In pseudostratified epithelium, cells exist in a single layer, but their nuclei travel between apical and basal surfaces, a process known as IKNM. In vertebrates, most cells possess single nonmotile primary cilium, which serves as critical regulator of signal transduction during development and homeostasis. Whereas a cell’s shape is defined by a global observation, round, cuboidal, polygonal, etc., this review focuses on the transcriptional mechanisms by which a cell can change its shape to execute its function within a developing organ.