GSTM1 and Hearing impairment: Cisplatin leads to loss of outer hair cells in the cochlea [28], and thereby also to hearing impairment [4], which was limited by absence of GSTM1. In the subgroup of 173 TCSs in whom audiometry was performed such a beneficial effect of non-functional GSTM1 was found for objectively measured cisplatin-induced hearing impairment, which in addition was strongly associated with the genotype GSTP1-GG [22].