The National Cancer Institute has identified a natural antibody, X5, that seems to gum up HIV's entry into CD4 cells. The antibody acts upon gp120, the glycoprotein that gives HIV a boost into CD4 cells. X5 was tested on a variety of HIV strains and proved able to zap the buggers' ability to hijack the cell. Researchers are still figuring out its exact mechanism, but it would be a great leap forward to have an agent that targeted the virus directly rather than the HIV-infected cell.