For over 20 years it has finally become accepted that primary cilia are without doubt important cellular organelles, involved in signalling both intrinsically and extrinsically. The consequences of their agenesis, incorrect assembly and dysfunction only began to be fully appreciated after 2000, although this had been demonstrable over the previous two decades. Before 1980, biologists at large thought the organelle rudimentary or vestigial; how a well-developed cilium could be so slated beggars belief. Many pathological conditions have implicated the primary cilium as either a major or contributing factor, ranging from kidney malfunction (e.g. polycystic kidney disease) to mental aberrations. However, the questions of how the recognition of their prevalence, their sensory function, and their pathological involvement finally emerged as substantiated and verifiable facts needs to be addressed because what happened before the 1980s, and then notably between 1980 and 2000, can help guide research towards answering further questions on these issues. Here the intention is to focus on the salient findings (the turning points) that brought about changes in our knowledge of primary cilia. The literature on them is growing fast, with the total moving towards 20,000 reports, of which > 60% have been published in the last decade. PubMed indicates that nearly 1000 papers were published in 2020 alone. We also have to appreciate that the primary cilium can assume many different forms, each of which means that there must be many genes responsible for their development and final structure. This also suggests that there are many more functions than are currently known in both their sensory reception and signalling properties, probably for many highly specialised purposes. Malfunctioning in any of these roles will undoubtedly uncover further pathological conditions.

20多年来，人们终于认识到初级纤毛无疑是重要的细胞器，参与内在和外在的信号传导。它们的发育不全、不正确的组装和功能障碍的后果直到 2000 年才开始被充分认识到，尽管这在过去的二十年中已经得到了证明。 1980 年之前，生物学家普遍认为细胞器是初级的或退化的。一个发育良好的纤毛怎么会如此令人难以置信。许多病理状况都表明初级纤毛是主要因素或促成因素，范围从肾功能障碍（例如多囊肾病）到精神失常。然而，如何认识到它们的患病率、感觉功能和病理参与最终如何成为已证实和可验证的事实，这些问题需要解决，因为 20 世纪 80 年代之前，特别是 1980 至 2000 年间发生的事情可以帮助指导研究回答有关这些问题的进一步问题。这里的目的是重点关注使我们对初级纤毛的认识发生变化的显着发现（转折点）。有关它们的文献正在快速增长，报告总数已接近 20,000 份，其中 > 60% 是在过去十年中发表的。 PubMed 表示，仅 2020 年就发表了近 1000 篇论文。我们还必须认识到，初级纤毛可以呈现多种不同的形式，每种形式都意味着必须有许多基因负责其发育和最终结构。 这也表明它们的感官接收和信号传递特性比目前已知的功能要多得多，可能用于许多高度专业化的目的。这些角色中的任何一个出现故障无疑都会暴露出进一步的病理状况。