Cilia were immunostained with anti-Arl13b antibody (T. Caspary), and cilia size was determined by dividing the number of Arl13b-positive pixels by the number of nuclei per image. Ciliary levels of Gli2 and IFT88 were determined by immunostaining cells with anti-Gli2 (R&D Systems) or anti-IFT88 (ProteinTech Group) antibodies. Analyses of mitotic spindles and kinetochore-microtubule attachments in fixed cells were performed as described26 (link), and real-time confocal microscopy was conducted with NIH-3T3 cells stably expressing GFP-tubulin. Melanosome and peroxisome motility studies were conducted as reported19 (link),20 (link).