![Polarized crystals (photographed through a microscope) of the drug 2-3 dideoxyadenosine A microscopic view of an antiretroviral drug](/sites/nihrecord/files/styles/thumbnail_small/public/2023/October-27/20231027-cvr-nci-antiviral-drug.jpg?itok=gIgEerbf)
On the Cover
Polarized crystals (photographed through a microscope) of the drug 2-3 dideoxyadenosine, also known as ddA, a drug that is closely related to AZT or azidothymidine. The antiviral effect of ddA against HIV was discovered at the National Cancer Institute.
Larry Ostby, NCI