Here, we find that pattern of photoreceptor death, most relevant aspects of phase 1 remodeling, and corresponding ERG signature, are all very similar to those already described in rd1 and rd10 mice during the first month of life19–22 and to other mutants23, therefore we conclude that these are primary, pathognomonic signs of RP, independently from the age of onset of the phenotype and from the causative mutation. This evidence concerns the gene PDE6B and retinitis pigmentosa 1.