CD4 and AIDS: For example, in humans, two MHC haplotypes, HLA -A*11-C*04-B*35-DRB*01-DQB1*01 and HLA -A*01-C*07-B*08-DRB1*03-DQB1*02 (the 8.1 Ancestral Haplotype or AH); are associated with a more rapid progression to Acquired Immunodeficiency Syndrome (AIDS) [11–13], and strongly associated with a rapid decline of CD4+ T cells and development of HIV-related symptoms [14].