CAT and noise induced hearing loss: Our results showed that rs611419 polymorphism and rs3735715 polymorphism (in GRHL2), rs208679 polymorphism (in CAT), rs3813346 polymorphism (in EYA4) was significantly associated with susceptibility to NIHL, and rs2227956 polymorphism (in HSP70) were found to be significantly associated with susceptibility to NIHL in the Caucasian, while the other 20 gene polymorphisms were not found to have significant correlation with NIHL.