is a retroviral aspartyl protease (retropepsin) that is essential for the life-cycle of HIV, the retrovirus that causes AIDS.[2][3] HIV protease cleaves newly synthesized polyproteins at the appropriate places to create the mature protein components of an infectious HIV virion. Without effective HIV protease, HIV virions remain uninfectious.[4][5] Thus, mutation of HIV protease's active site or inhibition of its activity disrupts HIV’s ability to replicate and infect additional cells,[6] making HIV protease inhibition the subject of considerable pharmaceutical research.