AIDS is caused by HIV virus, which produces 12 different kinds of proteins. Organic compounds that interact with these proteins and interfere with virus reproduction are potential drugs for treatment of AIDS.

The APS synchrotron was used to determine the crystallographic structure of the Abbott Laboratories pharmaceutical known as Kaletra®.

Since FDA approval in 2000, Kaletra® has had positive impact on progression of the AIDS in patients infected with HIV virus. In 2002, Kaletra® became most-prescribed (“preferred”) drug in its class for AIDS therapy; it is a drug that helps turn a situation where patients are dying from AIDS into a situation where patients are living with AIDS.