Fortunately, the union operation of PepMapper complements the weakness of Intersection operation by joining the results from the two methods together to increase the size of potential epitopic sites. The Union operation produced the best performance in sensitivity but the worst in precision and specificity compared to that of the Intersection, MimoPro, and Pep-3D-Search (Tables 2  & 3) . This is because the increased size of potential epitopic sites brought in by the Union operation also contains more false positives in the candidates. Using Consistency defined in Equation (3) as an indirect sufficient condition to judge the likelihood of successful prediction of epitope by combining both Intersection and Union, our tests tend to support its usefulness in indicating the likelihood of successful prediction (Table 3) . Although the number of tests is still insufficient for us to draw any exclusive conclusion on its implication on epitope prediction, our initial analysis leads to the following indications: 