GRN and neuronal ceroid lipofuscinosis: Excessive PGRN production is associated with cancers that grow aggressively and metastasize early (He and Bateman, 1999; Yang et al., 2015; Serrero et al., 2016), while PGRN haploinsufficiency and homozygous loss of function states lead to adult-onset frontotemporal dementia (FTD) (Baker et al., 2006; Cruts et al., 2006) and childhood-onset neuronal ceroid lipofuscinosis (NCL) (Smith et al., 2012), respectively.