We previously observed that S phase entry following cell cycle exit and re-entry (after serum addition) was delayed in two Sensenbrenner syndrome cells (deficient in IFT43 or WDR35), which have impaired intraflagellar transport and cilia function, and in ORC1-deficient cells, which show very delayed cilia formation (16). Here, ORC1 is linked to cranioectodermal dysplasia.