Some potential candidates for involvement in disease resistance include genes already known to confer resistance to other viral infections (MHC-B locus genes, MX1, OASL and IFITM3), genes involved in apoptotic processes (TPD52L1, BCL2L1, FAIM2 and CIAPIN1) and others which could be potential candidates due to their known biology (e.g. DDT and CD4). This evidence concerns the gene CD4 and viral infectious disease.