Clinical staging and profiling is a diagnostic strategy that goes beyond the traditional dichotomy in medicine of merely focusing on the presence or absence of a disease. Disease staging extends this traditional dichotomy by defining where a patient lies along the continuum of the course of his or her particular illness. Successful examples include the general tumor, node, metastasis (TNM) classification in oncology, as well as the New York Heart Association (NYHA classes I-IV) functional classification system for patients with congestive heart failure. It enables clinicians to select treatments relevant to earlier stages because such interventions may be more effective and less harmful than treatments delivered later in the illness course. Profiling is a further refinement, as well as a necessary component of staging. Profiling refers to the characterization of a patient within a specific disease stage, which is relevant for its course and treatment choice. An example of profiling is estrogen receptor positivity in patients with breast cancer.