Recent clinical trials have adopted a gene replacement strategy in patients with OTOF mutations, one of the most common causes of nonsyndromic autosomal recessive hearing loss, also known as DFNB9.[28, 29, 30] Through the dual‐AAV strategy, the large OTOF cDNA (≈6 kb) can be delivered into the inner ear through the RWM. This evidence concerns the gene OTOF and autosomal recessive nonsyndromic hearing loss 9.