Component of the tectonic-like complex, a complex localized at the transition zone of primary cilia and acting as a barrier that prevents diffusion of transmembrane proteins between the cilia and plasma membranes. Part of the tectonic-like complex (also named B9 complex). Interacts with TUBG1. Highest expression in thymus and skeletal muscle. Also expressed in spleen, kidney, lung, heart, microglia and liver. Detected in brain (at protein level). Mice expressing reduced levels of the protein in the central nervous system and kidney develop perinatal triventricular hydrocephaly, polycystic kidney disease, lack functional intact cilia and die at the time of weaning. Belongs to the B9D family.