Luis Menéndez Arias is a Research Professor of the Consejo Superior de Investigaciones Científicas (Spanish National Research Council) and Group Leader at the Centro de Biología Molecular “Severo Ochoa” (CBMSO) in Madrid, where he has been working since March 1994. He studied biology at the Complutense University in Madrid, Spain, where he obtained his Ph.D. In September 1990, he moved to the Basic Research Program of the Frederick Cancer Research and Development Center (Frederick, MD, USA) where he conducted studies on the biochemical properties of retroviral proteases and their implications in virus maturation and antiviral therapy. Currently, he is Research Professor of the Spanish National Research Council and Group Leader at the Centro de Biología Molecular “Severo Ochoa” in Madrid, where he has been working since 1994. His research is mainly devoted to understanding structure-activity relationships in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT), elucidating mechanisms of HIV resistance to antiretroviral drugs, and understanding HIV replication fitness. Part of this work involved the development of engineered RTs with increased fidelity and/or thermal stability. These enzymes are currently used in biotechnological applications (ScriptoolsTM and SunScriptTM). Luis Menéndez-Arias is author or co-author of more than 100 peer-reviewed research papers, most of them related to retroviruses and antiretroviral therapy. He serves as Academic Editor of PLoS ONE, and is member of the Editorial Boards of Antimicrobial Agents and Chemotherapy, Antiviral Research, Antiviral Therapy, Journal of Biological Chemistry, Virus Research and Viruses.