CRABP1 and hearing loss disorder: These genes are known to be expressed in the cochlea and are relevant for inner ear physiology: Crabp1 is expressed during cochlear development and controls the intracellular concentration of free retinoids [53], [54] (key hormone regulators of inner ear embryogenesis [55]); Casq1 participates in the calcium buffering system that is upregulated to protect hair cells from noise trauma and lies within DFNA49, an autosomal dominant non-syndromic hearing loss locus [56]–[58]; and mutations in Sod1 are associated with early-onset hearing loss in mice [59].