In functional genomics, DNA microarray data is used to infer genomic regulatory networks [112] . For biological and efficiency reasons, gene expression is often quantized to two levels: on and off [113] . The multivariate methods of classification and feature selection discussed in the previous section have proved to be essential in the inference of such Boolean (binary) regulatory networks. By the same token, immunomic microarray data can be used to infer immunomic regulatory networks. As is true for gene expression, one may quantize each epitope response measured with an immunomic microarray at one of two levels-on (immunogenic/responder) and off (nonimmunogenic/ nonresponder)-leading to the inference of Boolean immunomic regulatory networks.