Protein or peptide hormones control and regulate diverse physiological processes and are important targets in clinical labs for diagnosing disease. There is a need to develop accurate measurement techniques to underpin the clinical assays, thereby increasing confidence in diagnoses, which increase favorable patient outcomes, reduce medical costs, and improve quality of life. This research focus encourages use of tools such as mass spectrometry and chromatographic techniques, and the development of novel sample treatment schemes aimed at advancing quantitative methods and harmonizing measurements approaches. The opportunity also includes the application and analysis of developed techniques to established clinical sample sets.