AP4E1 and ciliopathy: Twenty-four of the 140 potential ciliopathy genes were identified as being direct cilia interactants (Abi2, Ap4e1, Cdc42, Cdk4, Celsr1, Cops7a, Cyba, Dtnbp1, Dync1li1, Ehmt1, Folr1, Herc1, Klhl5, Mapt, Mib2, Myo7a, Prkab1, Ptp4a1, S1pr3, Sik3, Sugp1, Ube2a, Wsb2, and Xbp1) based on STRING protein interaction analysis (Fig. 1b).