A more recent example, and one relevant to neurodegenerative diseases and the endo-lysosomal network, is provided by mutations in the Sortilin-Related Receptor 1 (SORL1), which has recently emerged as only the fourth gene that causes a rare, early-onset form of Alzheimer's disease [1,2]. Here, SORL1 is linked to early-onset autosomal dominant Alzheimer disease.