Zhimin Tim Cao, MD, PhD, DABCC, FADLM served for 21 years at Wadsworth Center, New York State Department of Health as a research scientist, section director and assistant director of the Center for Endocrinology Category, later as Clinical Chemistry Laboratory Director. One of his research interests was accuracy-based proficiency testing. He has first-authored several publications relevant to the area of this Scientific Short including: Accuracy-based proficiency testing for estradiol measurements. Clin Biochem. 2024 PMID:38043696; Accuracy-based proficiency testing for testosterone measurements with immunoassays and liquid chromatography-mass spectrometry. Clin Chim Acta 2017. PMID:28288785; Impact of testosterone measurement standardization efforts assessed by accuracy-based proficiency testing. Clin Biochem. PMID:30928392; Dr. Cao is now director of Clinical Chemistry and also founder of Mass Spectrometry/Toxicology Laboratory at Upstate Medical University hospital. His current research interests include targeted and untargeted analysis using mass spectrometry.