MFSD8 and neuronal ceroid lipofuscinosis: Atrophy of the visual system is a common feature of all of the childhood-onset forms of NCL and is seen in CLN7 mutant mice (Jankowiak et al., 2016); again, this may reflect a conserved ancestral role for CLN7 and it will be interesting to determine whether CLN7 mutant flies suffer similar visual pathology.