DZIP1L (DAZ interacting zinc finger protein 1 like) is a basal body and transition zone protein essential for primary cilium formation and function 1. DZIP1L localizes to ciliary transition fibers, striking structures at the ciliary base that serve as a selective gatekeeping mechanism 1. The protein regulates ciliary protein entry by modulating transition fiber architecture and function, working synergistically with ANKRD26 to control the passage of both soluble and membrane proteins into the cilium 1. This function is critical for proper localization of polycystin-1 (PKD1/PC1) and polycystin-2 (PKD2/PC2) to the ciliary membrane 2. DZIP1L mutations cause autosomal recessive polycystic kidney disease (ARPKD), a rare form of cystic kidney disease 3. DZIP1L accounts for a minor subset of ARPKD cases, with mutations generally associated with moderate disease severity 4. The N-terminal domain is critical for proper protein localization and function, as mutations in this region lead to protein mislocalization and disease 5. Unlike PKHD1-associated ARPKD, patients with DZIP1L mutations typically lack significant liver involvement 5. Genetic testing of DZIP1L should be included in multigene panels for cystic kidney disease evaluation 5.