Screenshot from the Web service for the proteochemometric susceptibility model of HIV protease inhibitors. The publicly available prediction service takes an HIV protease sequence as input and predicts its susceptibility to seven protease inhibitors using the proteochemometric model. The output is graphical and indicates any anomalies in the submitted sequence with respect to the data in the model. Shown are results for a protease with the quadruple mutation 24I, 46L, 54V, and 82A. The Web service can be found at .