TSC1 and retinitis pigmentosa 1: Remarkably, cone death was brought to a halt for at least 1 month3 in the fast retinal degeneration-1 (rd1) mouse model of RP, which harbors a mutation in the rod-specific phosphodiesterase-6-β gene (Pde6β).6 As activation of mTORC1 affords a mutation-independent approach to prolong vision,3 we investigated why in rd1 mice with loss of Tsc1, cone death resumed between 2 and 4 months of age.