where Z is Z-score of each spot, I is raw intensity of the spot, and m and r are mean value and standard deviation, respectively, of ''blank'' spots on the microarray. Each protein has 2 duplicated spots. The identified hits were defined as those proteins with Z-scores for both spots at or above the 5 SD cutoff. When comparing the appearance frequency for individual antigens for HIV/KS patients vs lymphoma or healthy normals, the enrichment score was reflected by ES 5 f ks =f 1 . We adopted binominal probability to calculate the significance between comparisons such that