ΔCS mice have an exchange mutation in the FasL metalloproteinase cleavage site that prevents cleavage of mFasL, resulting in increased levels of mFasL and no sFasL.22 Therefore, we speculated that even in the resistant B6129SF2 mouse strain, the increased levels of mFasL and the lack of sFasL in the B6129 ΔCS mice would result in more photoreceptor death following retinal detachment as compared with B6129 WT mice. The gene discussed is FASLG; the disease is retinal detachment.