The recent report “The Consensus Coding Sequences of Human Breast and Colorectal Cancers” published in Science represents the first unbiased systematic mutational analysis of human genome at any disease states after the completion of The Human Genome Project. It was tentatively discussed how to take advantage of the candidate cancer genes found in this study in discovery of novel targets of therapeutic drugs. In addition, the penitential values of the candidate cancer genes in identification of patients at high risk of cancer, and in renewing classification of tumors based on underlying molecular mechanisms are introduced.