July 14, 2021 marks the 220th anniversary of an outstanding scientist and physician — Johann Peter Müller. It is thanks to his works that we know what the «endocrine gland» is, understand the taxonomy of the animal world and the essence of ontogenesis. Professor, researcher, wonderful teacher, director of the anatomical and physiological museum of the University of Berlin — he succeeded in any role in life. Mueller’s discoveries were recognized during his lifetime, textbooks were published under his leadership, and scientific articles were published. The value of the professor’s work is high to this day, which once again proves the colossal contribution of Johann Müller in the formation of world science.