IFTAP (intraflagellar transport associated protein), also known as C11ORF74, is a ciliary protein that interacts with the IFT-A complex to regulate intraciliary transport and BBSome localization. Mechanistically, IFTAP binds to the IFT-A complex via the IFT122 subunit and can be transported toward the ciliary tip in association with IFT particles, though most IFTAP localizes outside cilia at steady state 1. The protein is essential for BBSome entry into cilia, as IFTAP knockout cells show impaired BBSome ciliary localization 1. However, IFTAP appears to have limited functional roles in ciliary protein trafficking, as knockout mice display no obvious ciliary dysfunction phenotypes and GPCR trafficking is unaffected 1. Clinically, IFTAP variants may contribute to disease susceptibility; a polymorphism (rs1818545*A) near IFTAP was associated with susceptibility to endemic pemphigus foliaceus in a Brazilian population, suggesting involvement in immune-related pathways 2. IFTAP is conserved across vertebrates but absent in non-vertebrate ciliated organisms, indicating a vertebrate-specific role 1. The functional significance of IFTAP in human ciliopathies remains to be fully characterized.