Interestingly, elevated cochlear adenosine levels in untreated mice were associated with enhanced expression of Adora2b gene encoding A2BR. Treatment with an A2BR antagonist significantly improved hearing loss in Ada-null mice, nerve fiber and myelin density, suggesting that the activation of A2BR aggravates sensorineural hearing loss (SNHL) [81]. This evidence concerns the gene ADA and sensorineural hearing loss disorder.