TMEM67 is a transmembrane protein essential for primary ciliary structure and function 1. It localizes to the ciliary transition zone and serves dual roles: regulating ciliogenesis through centrosome migration, cilia length control, and transition zone assembly, while also modulating non-canonical Wnt signaling 2. TMEM67 undergoes proteolytic cleavage by ADAMTS9, generating a C-terminal fragment that promotes ciliogenesis and a non-cleaved form regulating Wnt signaling; this separation of functions is clinically significant 2. Core fucosylation by FUT8 stabilizes TMEM67 protein levels by preventing autophagy-mediated degradation, ensuring proper ciliary localization 3. TMEM67 mutations cause multiple ciliopathies including Meckel syndrome, Nephronophthisis-11, Joubert syndrome, and Bardet-Biedl syndrome 45. Gene-phenotype correlations show TMEM67 mutations associate with liver fibrosis and coloboma in Joubert syndrome patients 4, and NPHP11/TMEM67 patients have a median age of end-stage kidney disease onset of 19 years 6. These findings highlight TMEM67's critical role in ciliogenesis and explain its involvement in multisystem ciliopathy pathogenesis.