Primary cilia are solitary, immotile sensory organelles present on most cells in the body that participate broadly in human health, physiology and disease. Cilia generate a unique environment for signal transduction with tight control of protein, lipid and second messenger concentrations within a relatively small compartment, enabling reception, transmission and integration of biological information. In this Review, we discuss how cilia function as signalling hubs in cell–cell communication using three signalling pathways as examples: ciliary G-protein-coupled receptors (GPCRs), the Hedgehog (Hh) pathway and polycystin ion channels. We review how defects in these ciliary signalling pathways lead to a heterogeneous group of conditions known as ‘ciliopathies’, including metabolic syndromes, birth defects and polycystic kidney disease. Emerging understanding of these pathways’ transduction mechanisms reveals common themes between these cilia-based signalling pathways that may apply to other pathways as well. These mechanistic insights reveal how cilia orchestrate normal and pathophysiological signalling outputs broadly throughout human biology.

初级纤毛是孤立的、不动的感觉细胞器，存在于体内的大多数细胞上，广泛参与人类健康、生理和疾病。纤毛产生独特的信号转导环境，在相对较小的隔室内严格控制蛋白质、脂质和第二信使浓度，从而实现生物信息的接收、传输和整合。在这篇综述中，我们以三种信号通路为例，讨论了纤毛如何作为细胞间通讯的信号中枢：纤毛 G 蛋白偶联受体 (GPCR)、刺猬 (Hh) 通路和多囊蛋白离子通道。我们回顾了这些纤毛信号通路的缺陷如何导致一组被称为“纤毛病”的异质性疾病，包括代谢综合征、出生缺陷和多囊肾病。对这些途径转导机制的新认识揭示了这些基于纤毛的信号传导途径之间的共同主题，这些主题也可能适用于其他途径。这些机制见解揭示了纤毛如何在整个人类生物学中广泛协调正常和病理生理信号输出。