Atoh1 is a vital gene for HC regeneration in the inner ear, and the first trial of gene therapy for deafness in humans based on delivering the recombinant adenovirus 5 vector containing the human cDNA of atonal transcription factor (Hath1), a homolog of Atoh1, is currently underway in the US (NCT02132130). The gene discussed is ATOH1; the disease is deafness.