It is with deep sadness that we received the news about prof. Leslie Paul Kozak, outstanding biochemist, employee of our Institute in 2011-2016, passing away on July 13, 2023.

Born in Canada, Prof. Leslie Kozak came to Poland after 45 years of research work in the United States. He received his PhD in biochemistry from the University of Notre Dame in Indiana. As the Assistant Professor at the Jackson Laboratory in Bar Harbor Maine, he began his independent research into obesity, thermogenesis, and brown adipose tissue. At the Pennington Biomedical Research Center in Baton Rouge, he continued research on the role of thermogenesis in the treatment of diet-related diseases, including type 2 diabetes and obesity.

Prof. Kozak was employed at our Institute as an outstanding specialist under the REFRESH project, funded in the Widening action of the 7th EU Framework Programme. As a laureate of the WELCOME grant of the Foundation for Polish Science, he created a new laboratory at the Institute and established a scientific group to study thermogenesis in the aspect of genetic mechanisms regulating the formation of brown adipose tissue. He authored over 200 publications in world journals, including Nature, Nature Medicine.

For his research achievements while working at the Institute, in 2015, he received the Medal of Merit for the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences.

Prof. Leslie Kozak will remain in our memory as an outstanding scientist, a devoted mentor to the young generation of researchers and a kind-hearted colleague.