This demonstration is part of a series of activities and demonstrations focusing on various aspects of the human immunodeficiency virus (HIV) life cycle. This activity focuses on HIV protein production. Two HIV genes (the gag and pol genes) are transcribed into a single RNA molecule that is then translated into a polyprotein. The Gag-Pol polyprotein is the cleaved by the HIV protease enzyme to generate six proteins essential for assembling new virus particles. This demonstration models the production of these six proteins and also shows how inhibiting HIV protease activity prevents the production of new viruses. Protease inhibitors are a class of drugs used to treat HIV infection.