All the members of the human DSPA are located on chromosome 11 except for DSPA2d which resides on chromosome 12. The genes of the other subfamilies are not enriched on any chromosome. Several features are common to all the eukaryotic Dispanin proteins ( Figure 3 ). They comprise two transmembrane helices that are predicted between 20 and 30 amino acids in length with the second helices often being slightly longer. The Dispanins are rich in both glycosylation-and phosphorylation sites that predominantly are found on the Nterminus. The N-terminus is often long (.100 amino acids) compared to the C-terminal (,10 amino acids) and both are always oriented towards the outside of the cell.