CDK20 and short rib-polydactyly syndrome: Although the precise functional relationship between the Ccrk-Mak/Ick pathway and IFT-A/cytoplasmic dynein-2 remains unclear, mutations in the genes encoding IFT-A and cytoplasmic dynein-2, and ICK are associated with a shared human ciliopathy, short rib-polydactyly syndrome (93).