With great sorrow we announce that on 22 October 2019 prof. MUDr. Josef Marek, DrSc., Emeritus chief III. Department of Internal Medicine - Departments of Endocrinology and Metabolism of General Teaching Hospital and 1st Faculty of Medicine, Charles University. At III. he joined the internal clinic in 1965, he worked as a secondary, assistant professor, associate professor and professor at the clinic, and from 1990 to 2001 he held the position of head of the clinic. At the clinic, Professor Marek became one of the most prominent pupils of the founder of Czech endocrinology, Professor Charvát.