The era of genomics-based medicine promises to provide molecular tests that will permit precision medicine. However, in 2015, it is not clear what the terms genomics-based medicine, molecular tests, or precision medicine mean. In this report, we review the definitions of these terms and other important semantics relative to what it takes to get a tumor biomarker into standard clinical practice, and the potential clinical trial designs that are being considered to determine if tumor biomarker tests based on next-generation sequencing actually provide benefit to patients with cancer.