IQ calmodulin-binding motif-containing protein 1 (IQCB1) is a nephrocystin protein that interacts with calmodulin and the retinitis pigmentosa GTPase regulator protein. IQCB1 has a central coiled-coil region and two calmodulin-binding IQ domains. It is localized to the primary cilia of renal epithelial cells and connecting cilia of photoreceptor cells. IQCB1 is thought to play a role in ciliary function. Defects in this gene result in Senior-Loken syndrome type 5 [taken from NCBI Entrez Gene (Gene ID: 9657)].