TRAT1 and infection: Because the main role of the MHC class I and TRIM genes is the same in eliminating infection from viral particles [3], [63] and the proximity of genes within a MHC region has been suggested to allow co-evolution between the genes [56], [57], our finding in organisation between MHC class I and TRIM genes may indicate an advantageous role in their immune function in vertebrates, especially in antiviral immune responses.