Professor Jeffrey D Zajac is a clinical academic with research interests in both clinical endocrinology and molecular endocrinology. He has focussed on steroid and peptide hormone action and effects. He has investigated: The androgen receptor (AR) structure and function and the effect of mutations on human illness. He has done extensive studies on testosterone and men's health. Calcium regulating hormones, parathyroid hormone, PTHrP, and calcitonin. He was part of the team which first isolated PTHrP and has investigated the physiological role of the calcitonin receptor. Type 2 diabetes looking at glucose toxicity Transgender animal models and transgender health He trained at the University of Melbourne for his undergraduate degree and PhD and had a postdoctoral appointment at the Massachusetts General Hospital in the Harvard Health system. During his career he was Head of the Department of Medicine (University of Melbourne) as well as Head of the Department of Medicine, (University of Melbourne) at Austin Health. He was also director of the Department of General Medicine and Director of the Department of Endocrinology. He is now happily retired and pursuing interests in clinical endocrinology and endocrine research.