A "abnormal" variation of a protein found on white blood cells called the CKR5 co-receptor is being studied for an apparent HIV anti-infective quality. Researchers from the Aaron Diamond AIDS Research Centre in New York have found a high correlation of the protein with HIV resistance. About one in 100 Caucasians are thought to carry the gene combination that seems to produce a near immunity to the virus. Another 20 percent have one-half the genetic complement which researchers think lends partial immunity. No other effect of having the variant protein has been noted. A number of individuals with very high risk for HIV infection who never tested positive were involved in the study. Only a small number of these showed this type of protein; researchers still don't have any idea why the rest of the volunteers seem to be immune.

Cell, August 9, 1996.