This issue of Clinics in Laboratory Medicine will focus on Clinical Pathology and is edited by Geza S. Topics include, but are not limited to, Steroid measurement / Salivary cortisol measurement, Protein testing by LCMSMS, LCMSMS in the Clinical Laboratory, Laboratory Standards for Clinical LCMSMS, The need to teach LCMSMS to clinical laboratory scientists, MALDI-TOF in the clinical laboratory, MALDI TOF MS in the clinical microbiology laboratory, LCMSMS method development consideration in clinical laboratory practice, Cancer diagnosis using mass spectrometry, Adulteration and LCMSMS drug testing, Diagnosis of inherited metabolic disorders using LCMSMS, Harmonization of LCMSMS protein assays, Vitamin D testing by LCMSMS versus by immunoassay, Pain management testing by LCMSMS, and Development of FDA approved clinical mass spectrometer.