According to the "distorted key" theory (K.C. Chou: Analytical Biochemistry 1996, 233, 1-14), the information of HIV protease cleavage sites in proteins is very useful for designing drugs against AIDS (acquired immunodeficiency syndrome). Using this web server, users can easily predict the cleavage sites for any query protein sequence by HIV-1 or HIV-2 protease, as illustrated by the figure below:

Figure 1. The cleavage site is located between residues R1 and R1' .