It is my hypothesis that vulnerability to HIV infection and AIDS results from low dehydroepiandrosterone (DHEA). Furthermore, it is my hypothesis that testosterone interferes with the availability of DHEA. Therefore, the ratio of these two hormones is directly involved in HIV infection and AIDS. (My explanation of AIDS contains the citations supporting my statements herein.) Because chimps produce more DHEA and less testosterone than humans, I have suggested this is why they are not easily infected by the HIV. Recently, research has produced the hypothesis that a mutation in the gene that produces the cell surface receptor, CCR-5, confers resistance to the HIV. (CCR-5 receptors are one of the mechanisms whereby the HIV enters target cells. If the receptor is defective, the attachment of HIV is reduced.) People of European descent exhibit a higher incidence of this mutation than other groups. This has resulted in the hypothesis that this difference in gene distribution accounts for reduced incidence of HIV infection of individuals of European descent and the high incidence of HIV infection and AIDS in other areas, especially Africa. http://www.anthropogeny.com/Chimpanz...stosterone.htm