The primary cilium: A small yet mighty organelle

Abstract

Primary cilia are small, cylindrical membrane protrusions on most vertebrate cell types. Despite an unassuming appearance, this organelle has proven to be a veritable nexus of tightly regulated cell-signal reception between the epithelium and mesenchyme. In this issue, Lehman et al. describe the necessity of Ift88 and intraflagellar transport for signal reception of the sonic hedgehog pathway in the dermal papilla of developing hair follicles.