KIAA0319L encodes a type I transmembrane protein that serves as a universal receptor for adeno-associated virus (AAV) infection across multiple serotypes 1. The protein facilitates rapid endocytosis from the plasma membrane and trafficking to the trans-Golgi network, directly binding AAV particles to enable viral entry 1. KIAA0319L interacts with the FAM91A1-TBC1D23 complex to regulate endosome-to-Golgi trafficking, which is crucial for axonal growth and neuronal development 2. Genetic ablation of KIAA0319L renders mammalian cells and mice highly resistant to AAV infection, highlighting its essential role in viral gene therapy vectors 1. The gene has clinical significance in multiple diseases: it serves as a susceptibility locus for autoimmune conditions including systemic sclerosis and systemic lupus erythematosus, showing overexpression in patient blood cells 3. KIAA0319L is also implicated in developmental dyslexia, with in utero knockdown experiments causing neuronal migration defects and periventricular heterotopia formation 4. Additionally, knockout mice lacking KIAA0319L display auditory processing deficits and abnormal brainstem responses, suggesting roles in auditory system function 5. Some studies have explored associations with recurrent pregnancy loss, though results require further validation 6.