In 2020, Matter and Radiation at Extremes (MRE) reached a particularly important milestone when it received its first official impact factor of 2.931, which indicates the high quality of the papers published to date. This outstanding success can be attributed to the strong commitment and valuable contributions from all the reviewers. The Editors of MRE wish to express their deepest gratitude to the following individuals who generously provided advice on manuscripts as reviewers for MRE in the year of 2020.