In models of retinitis pigmentosa, increased CASP3 activity caused PR degeneration in transgenic S334ter rats, tubby mice, rds and rd mice with concomitant activation of CASP8 and mitochondrial release of cytochrome C. In contrast, CASP3-independent apoptosis and rod death has been reported in rd mice (reviewed by [11]). Here, CYCS is linked to retinitis pigmentosa.