Protease inhibitors are molecules that block the activity of enzymes called proteases, which are responsible for breaking down proteins in the body. Protease inhibitors have been studied for their potential therapeutic applications in various diseases, including viral infections such as HIV/AIDS, cancer, and inflammatory conditions. By inhibiting proteases, these molecules can interfere with the replication of pathogens or the progression of certain diseases. Protease inhibitors can be synthetic compounds or naturally occurring substances and are a focus of research in drug development and biomedical science.