IGF1 and hearing loss disorder: Following ROS production in the inner ear, changes in miRNAs alter mRNA expression; specifically, upregulation of miR-29a, miR-200c, and miR-17 occurs which in turn, downregulates insulin-like growth factor 1 (IGF-1), alters (IGF-1) mediated signaling and contributes to hearing loss (Ushakov et al., 2013).