eLife Assessment
In this valuable study, the authors build on previous work demonstrating that the microtubule-associated protein CKAP2 functions at the mitotic spindle to regulate microtubule dynamics for proper chromosome segregation. Here, the authors show that CKAP2 and its paralog CKAP2L also function at the cilium to regulate cilium formation and Hedgehog signaling. The writing is clear, the experiments and data are generally convincing, and the proper data analysis is carried out; however, the evidence supporting the proposal that CKAP2 and CKAP2L compensate for each other is incomplete. Overall, the findings advance the field in our knowledge of microtubule-associated proteins with roles in both the mitotic spindle and the cilium.