There are three SorCS genes that have diverse, partially overlapping functions in the central nervous system. In the developing and mature central nervous system, SorCS1, SorCS2 and SorCS3 genes are expressed in a combinatorial, non-overlapping pattern. SorCS proteins show homology to the mosaic receptor SorLA and the neurotensin receptor sortilin, based on a common VPS10 domain, which is the hallmark of the SorCS receptor family. SorCS2 (sortilin-related VPS10 domain containing receptor 2) is a 1,150 amino acid single-pass type I membrane protein that is highly expressed in brain and kidney. Containing six BNR repeats and a single PKD domain, SorCS2 is encoded by a gene that maps to human chromosome 4, which encodes nearly 6% of the human genome and has the largest gene deserts (regions of the genome with no protein encoding genes) of all of the human chromosomes.