Dr. Perez is a colorectal surgeon with an intensive research activity aiming at designing new strategies for the treatment of rectal cancer based on scientific evidence. In particular, he was in a position to contribute, together with a group of collaborators, to the understanding of specific mechanisms of rectal cancer response to neoadjuvant chemoradiation therapy. After obtaining his medical degree and surgical training at the University of S∆o Paulo School of Medicine in Brazil, Dr Perez joined a team of surgeons led by Prof. Angelita Habr-Gama at the University that were already conducting studies related to the treatment of rectal cancer. The environment provided by this association, where he worked both as a surgeon and researcher allowed him to obtain his PhD degree. Dr. Perez was then awarded a prestigious grant by State of S∆o Paulo Research Foundation that made possible the successful conduction of his post-doctoral studies. During that period, Dr Perez was directly involved in prospective and retrospective studies focused on the clinical, surgical and bio-molecular features of these tumors that may respond completely to chemoradiation therapy. These contributions have been significant to the development of alternative treatment strategies to patients with this disease. These patients historically almost inevitably required a radical surgical procedure with significant morbidity and quality of life consequences. After the group_s contributions, there is a hope that a proportion of these patients may now be spared from these procedures and offered a chance of cure with chemoradiation alone. More recently, Dr Perez has also joined the Ludwig Institute for Cancer Research in S∆o Paulo where he develops a close collaboration with scientists in an effort to provide clinically relevant genetic testing and monitoring of patients with this disease. His numerous contributions to high-impact peer-reviewed scientific journal have been consistently cited and received awards in national and international meetings. Since 2010, Dr Perez has been appointed to the Editorial Board of the journal Diseases of Colon & Rectum. In 2014, Dr Perez and his group have received the 2013 Impact Paper of the Year Award related to one the contributions to that same journal.