For this guest issue, Prof. Antonelli assembled a panel of international expert contributors to discuss current aspects of immunoendocrinology. There is increasing awareness of the intricate and intertwined relationship between the endocrine and immune system. In part, this is caused by an explosion of various immunotherapies including cellular immunotherapy (for instance, sipuleucel-T (Provenge), tisagenlecleucel (Kymriah), axicabtagene ciloleucel (Yescarta)), antibody-based therapy (i.e. rituximab (Rituxan, Mabthera), atezolizumab (Tecentriq), avelumab (Bavencio), ofatumumab (Arzerra), alemtuzumab (Campath-1H), durvalumab (Imfinzi), ipilimumab (Yervoy), tremelimumab, pembrolizumab, nivolumab (Opdivo)), cytokine therapy (i.e. interferon, interleukin-2), combination immunotherapy, and others. Among antibody based immunotherapies are the checkpoint inhibitor antibodies with ipilimumab being the first antibody approved by the Federal Food and Drug Administration (FDA). More and more immune-related adverse events of immune checkpoint inhibitor treatment are being unraveled and algorithms for acute management of endocrine complications have been proposed [1-8]. My first encounter with immunology occurred while studying at the Friedrich-Alexander University of Erlangen-Nuremberg in the 1980s and rotating through the Department of Medicine headed by Professor Joachim R. Kalden, who in 1970 reported on the effect of hypophysectomy on the immune system in male Sprague-Dawley strain rats [9]. Many fellow immunologists and rheumatologists trained under Prof. JR Kalden have risen to the top of the field [10-12]. My next immunological encounters, including the occurrence of bullous pemphigoid after treatment with furosemide, happened during residency training at the Ohio State University Medical Center [13] followed by the National Institutes of Health (NIH) which had the largest impact on my education in immunology and its intersection with endocrinology [14]. At the NIH I met many immunology and other experts, including Profs. George Chrousos, Ronald Wilder, Esther Sternberg, Ilias Elenkov, Philip Gold, Julio Licinio, and Thomas Fleisher [15-17]. After departing the NIH and spending a few years in Germany, I had the pleasure to collaborate with visceral and thoracic surgeon expert Prof. Ott and we published a study showing that converting liver transplant recipients from cyclosporine A therapy to steroid-saving tacrolimus monotherapy caused a decline in mean serum cholesterol and high density cholesterol levels but an increase in low density cholesterol serum concentrations, apparently without beneficial effect on the atherogenic lipid profile [18].