Originally Posted by digitalfantasies

and here we are..

Male Circumcision and Risk for HIV Transmission

Several types of research have documented that male circumcision significantly reduces the risk of HIV acquisition by men during penile-vaginal sex.

Biologic Plausibility

Compared with the dry external skin surface, the inner mucosa of the foreskin has less keratinization (deposition of fibrous protein), a higher density of target cells for HIV infection (Langerhans cells), and is more susceptible to HIV infection than other penile tissue in laboratory studies.... and so one

Source: cdc.gov (center for disease control and prevention)