On 13 July 2020, prof. Grzegorz Marek Wilczyński, Grześ, an outstanding, creative, and successful researcher, has passed away. Grześ came to my Laboratory, as a student of the Warsaw Medical University, in the mid-1990s, to investigate the phenomenon of, just discovered by us, programmed neuronal death in the brain of adult mammals. After graduating from medical studies in 1997, he completed an internship at the University of Southern California in Los Angeles, USA, and based on the research conducted over there, he prepared a doctoral dissertation defended at the Warsaw Medical University in 2002. Between 1997 and 2006, he worked at this University in the Department of Pathology, while being in constant contact with the Nencki Institute. Grześ carried out research in two areas: experimental oncology and neurobiology. In 2006, after winning an international competition, he became the head of the Laboratory of Molecular and Systemic Neuromorphology at the Nencki Institute. Initially, he worked closely with our team, especially investigating the participation of matrix metalloprotease MMP-9, in the development of epilepsy. This research resulted in several significant publications (including widely recognized and appreciated work: Wilczynski et al., Journal of Cell Biology, 2008) and a habilitation prepared based on these studies. Apart from this, he gradually developed his own research topic concerning the three-dimensional structure of chromatin and its microscopic imaging. Grześ has achieved great success in this area, as shown, among others, through authorship in a highly cited publication in Cell in 2015, or his recent leading work in Nature Communications (2020), as well as a joint, very prestigious grant from the Human Frontiers Science Program, obtained with Yijun Ruan from the USA and Angel Barco from Spain. In total, Grześ has published over 60 works from the Nencki Institute, seven of which have so far been cited more than 100 times. Grześ was very respected, widely liked and devoted friend and colleague of ours, elected to the Scientific Council and actively involved in the realization of the greatest challenges we faced, including the CN CePT project (Centre for Neurobiology, Centre for Preclinical Research and Technology) and the latest project to create at the Nencki Institute, the National Centre for Advanced Analysis of Biological and Biomedical Imaging. Involvement in the development of modern microscopic techniques was a great passion of Grześ. His death is a great, immense loss for the scientific community in Poland and worldwide.

Grześ, we will miss you …

Leszek Kaczmarek