In response to stress the complex dissociates, HSF1 is activated and translocates to the nucleus where it binds to promoter regions of heat-shock genes triggering their expression.27 Especially HSP25 and HSP70 exert important roles in the retina by protecting cells against oxidative stress and even retinal degeneration.16, 17 Incubation of 661W cells with KRIBB11, a specific inhibitor of HSF1 activation, repressed the induction of HSP70 and HSP25 under the condition of oxidative stress. This evidence concerns the gene HSPB1 and retinal degeneration.